Difference between revisions of "Non-malignant skin disease"

From Libre Pathology
Jump to navigation Jump to search
(rm broken)
 
(349 intermediate revisions by the same user not shown)
Line 1: Line 1:
'''Non-malignant skin disease''' is relatively common.  The pathology may or may not be specific.  Some diseases require clinical information to diagnose.
'''Non-malignant skin disease''' is relatively common.  The pathology may or may not be specific.  Some diseases require clinical information to diagnose.  


An introduction to dermatopathology is in the ''[[dermatopathology]]'' article.  [[Nevi]] (moles) and other melanocytic lesions are dealt with in the article ''[[melanocytic lesions]]''.
An introduction to dermatopathology is in the ''[[dermatopathology]]'' article.  [[Nevi]] (moles) and other melanocytic lesions are dealt with in the article ''[[melanocytic lesions]]''.  Inflammatory skin conditions are dealt with in ''[[inflammatory skin disorders]]''.


=Other=
==Lichen simplex chronicus==
{{Main|Lichen simplex chronicus}}


=Inflammatory conditions=
==Prurigo nodularis==
==Classification==
*Abbreviated ''PN''.
*Bullous.
*[[AKA]] ''chronic prurigo'' and ''picker nodule''.<ref name=Ref_Derm26>{{Ref Derm|26}}</ref>
*Interface.
*Nodular & diffuse.
*Spongiotic.
*Vasculitis.
*Perivascular.
*Panniculitis.
*Psoriasiform.
 
'''Tabular comparison of inflammatory skin disease (adapted from ''Brinster''<ref name=pmid18418089>{{cite journal |author=Brinster NK |title=Dermatopathology for the surgical pathologist: a pattern based approach to the diagnosis of inflammatory skin disorders (part I) |journal=Adv Anat Pathol |volume=15 |issue=2 |pages=76–96 |year=2008 |month=March |pmid=18418089 |doi=10.1097/PAP.0b013e3181664e8d |url=}}</ref>):'''
{| class="wikitable"
| '''Pattern'''
| '''Key histologic feature'''
| '''Subclassifications'''
| '''Example'''
|-
| [[Bullous disease|Bullous]]
| "Empty space"
| -Subcorneal<br>-Suprabasillar<br>-Subepidermal
| -Pemphigus foliaceus<br>-[[Pemphigus vulgaris]]<br>-[[Dermatitis herpetiformis]]
|-
| Interface
| Inflammation at DE junction
| -Vacuolar (minimal)<br>-Lichenoid (band-like)
| -[[Erythema multiforme]], [[SLE]]<br>-[[Lichen planus]]
|-
| Nodular & diffuse
| Nodular & diffuse
| ?
|
|-
| Spongiotic
| Edema between keratinocytes
| -Acute<br>-Subacute<br>-Chronic
| -Poison Ivy<br>-Nummular dermatitis<br>-Atopic dermatitis
|-
| [[Vasculitis]]
| Inflammation of vessel wall
| ?
| ?
|-
| Perivascular
| Inflammation around vessels
| ?
| ?
|-
| [[Panniculitis]]
| Inflamm. of adipose tissue
| -Septal<br>-Nodular
| -[[Erythema nodosum]]<br>-[[Erythema induratum]]
|-
| Psoriasiform
| Epidermal thickening<br>and long rete ridges
| -Regular<br>-Irregular
| -Psoriasis<br>-[[Lichen simplex chronicus]]
|}
Notes:
*''DE junction'' = dermal-epidermal junction.
*The "empty space" in bullous disease ''in situ'' is filled with fluid.
 
===Psoriasis===
====General====
*Can be subclassified.
 
DDx:
*Psoriasis vulgaris (most common).
*Psoriatic arthritis.
*Drug-induced.
*Others.
 
====Microscopic====
Features:<ref>{{Ref PBoD8|1191}}</ref><ref name=pmid18418089>{{cite journal |author=Brinster NK |title=Dermatopathology for the surgical pathologist: a pattern based approach to the diagnosis of inflammatory skin disorders (part I) |journal=Adv Anat Pathol |volume=15 |issue=2 |pages=76–96 |year=2008 |month=March |pmid=18418089 |doi=10.1097/PAP.0b013e3181664e8d |url=}}</ref>
*Regular epidermal thickening - as very long rete ridges (described as "test tube-morphology") - '''key feature'''.
**Epidermis between rete ridges thin ("thinning of suprapapillary plate").
*Parakeratosis.
*Thin/absent granular layer.
*Dilated blood vessels in superficial dermis.
*Neutrophil clusters (Munro microabscess).
 
==Seborrheic dermatitis==
===General===
*Very common.
 
===Microscopic===
Features:<ref>{{Ref PBoD8|1191}}</ref>
*Spongiosis (epidermal edema).
*Acanthosis (epidermal thickening).
*"Follicular lipping" = parakeratosis with neutrophils.
*Perivascular neutrophils and lymphocytes.
 
==Systemic lupus erythematosus==
===General===
===General===
*Systemic disease with multi-organ manifestations.
*Can be thought of as a localized/focal version of [[lichen simplex chronicus]] (LSC).
 
===Microscopic===
Features:
*Lymphocytic interface dermatitis.<ref>JAH. 20 February 2009.</ref>
*Basal layer vacuolation.<ref name=pmid18384217>{{cite journal |author=Crowson AN, Magro CM, Mihm MC |title=Interface dermatitis |journal=Arch. Pathol. Lab. Med. |volume=132 |issue=4 |pages=652–66 |year=2008 |month=April |pmid=18384217 |doi= |url=http://www.archivesofpathology.org/doi/full/10.1043/1543-2165%282008%29132%5B652%3AID%5D2.0.CO%3B2}}</ref>
*Intradermal mucin.
 
==Dermatomyositis==
:''For the muscle manifestations see: [[Neuromuscular_pathology#Dermatomyositis]]''.
===General===
*Complement mediated disease - membrane attack complex.
*Usually middle age.
*Associated skin rash is common.
**May precede or follow muscle pathology.
*Associated with malignancy in approximately 10% of cases.<ref name=pmid20398365>{{cite journal |author=Chen YJ, Wu CY, Huang YL, Wang CB, Shen JL, Chang YT |title=Cancer risks of dermatomyositis and polymyositis: a nationwide cohort study in Taiwan |journal=Arthritis Res. Ther. |volume=12 |issue=2 |pages=R70 |year=2010 |pmid=20398365 |pmc=2888225 |doi=10.1186/ar2987 |url=}}</ref>


===Gross===
===Gross===
*Have lesions on the knuckles - ''Gottron's papules''.
*Dome-shaped/raised - papular (<1 cm) ''or'' nodular (>1 cm).<ref>URL: [http://www.pediatrics.wisc.edu/education/derm/text.html http://www.pediatrics.wisc.edu/education/derm/text.html]. Accessed on: 23 August 2012.</ref>
 
===Microsopic===
Features:
*Lymphocytic interface dermatitis (inflammation at the dermal-epidermal junction).
*Loss of rete ridges.
 
==Lichen planus==
===General===
*An oral pathology.
*May be seen where the sun don't shine - penis,<ref name=pmid20082512>{{Cite journal  | last1 = Teichman | first1 = JM. | last2 = Sea | first2 = J. | last3 = Thompson | first3 = IM. | last4 = Elston | first4 = DM. | title = Noninfectious penile lesions. | journal = Am Fam Physician | volume = 81 | issue = 2 | pages = 167-74 | month = Jan | year = 2010 | doi =  | PMID = 20082512 }}</ref> vulva and vagina.<ref name=pmid20062629>{{Cite journal  | last1 = Gupta | first1 = R. | last2 = Bansal | first2 = B. | last3 = Singh | first3 = S. | last4 = Yadav | first4 = I. | last5 = Gupta | first5 = K. | last6 = Kudesia | first6 = M. | title = Lichen planus of uterine cervix - the first report of a novel site of occurrence: a case report. | journal = Cases J | volume = 2 | issue =  | pages = 9306 | month =  | year = 2009 | doi = 10.1186/1757-1626-2-9306 | PMID = 20062629 }}</ref>
 
Etiology:
*Autoimmune disease, T-cell–mediated.<ref>URL: [http://emedicine.medscape.com/article/1078327-overview http://emedicine.medscape.com/article/1078327-overview]. Accessed on: 11 September 2010.</ref>
 
Clinical:<ref name=Ref_PBoD8_1191>{{Ref PBoD8|1191}}</ref>
*6 Ps: pruritic (itchy), purple, polygonal, planar papules and plaques.
 
===Gross===
*Wickham striae = white lines/dots.
**Due to hypergranulosis.


===Microscopic===
===Microscopic===
Features:<ref>URL: [http://emedicine.medscape.com/article/1078327-overview http://emedicine.medscape.com/article/1078327-overview]. Accessed on: 11 September 2010.</ref><ref name=Ref_PBoD8_1192>{{Ref PBoD8|1192}}</ref>
*See ''[[lichen simplex chronicus]]''.
*Loss of basal cells (stratum basale) -- '''key feature'''.
*Loss of rete ridges/formation of pointed rete ridges "sawtoothing".
*Interface dermatitis (lymphocytes at dermal-epidermal junction).
*Hypergranulosis; stratum granulosum thickened (grossly seen as "Wickham stria" = white lines).
*Hyperkeratosis; stratum corneum thickened.
*Necrotic basal cell in dermis = colloid bodies = Civatte bodies.<ref name=Ref_PCPBoD8_604>{{Ref PCPBoD8|604}}</ref>


DDx:
DDx:
*[[Bullous disease]], subepithelial vesicular.
*[[Lichen simplex chronicus]] - a more diffuse process, not a raised lesion.
*[[Lichenoid keratosis]] - parakeratosis prominent.  


Notes:
===Sign out===
*Hyperkeratosis and hypergranulosis are not seen in [[erythema multiforme]].
<pre>
*Colloid bodies = cytoid bodies = Civatte bodies = hyaline bodies = apoptotic bodies.<ref>URL: [http://www.careforumwales.org/cell-carcinoma/histopathologic-terminology.html http://www.careforumwales.org/cell-carcinoma/histopathologic-terminology.html]. Accessed on: 28 August 2011.</ref>
SKIN LESION, LEFT CHIN, BIOPSY:  
**DDx: systemic lupus erythematosus, lichen planus, and [[graft-versus-host disease]].
- PRURIGO NODULARIS.
</pre>


Images:
====Micro====
*[http://commons.wikimedia.org/wiki/File:Lichen_planus_intermed_mag.jpg Lichen planus - intermed. mag. (WC)]
The sections show a raised lesion with compact hyperkeratosis and irregular acanthosis. Spongiosis is seen focally. There is minimal hypergranulosis.
*[http://commons.wikimedia.org/wiki/File:Lichen_planus_low_mag.jpg Lichen planus - low mag. (WC)].


==Lichen sclerosus==
There is no thinning of the suprapapillary plate and no dilated superficial blood vessels.  There is no interface activity.
{{Main|Lichen sclerosus}}


===Microscopic===
=Very common=
Features:<ref name=Ref_PBoD1065-6>{{Ref PBoD|1065-6}}</ref>
==Dermatomycosis==
*Subepithelial fibrosis - '''key feature'''.
:''Dermatophytosis'' redirects here.  
 
==Psoriasis==
===General===
===General===
*Chronic skin condition +/- systemic involvement:<ref name=Ref_PCPBoD8_603>{{Ref PCPBoD8|603}}</ref>
*[[microorganisms|Fungal infection]] of skin.
**[[Arthritis]].
**[[Myopathy]].
**Enteropathy, e.g. [[inflammatory bowel disease]].
**Syondylitic joint disease (spondylos = vertebrae<ref>URL: [http://medical-dictionary.thefreedictionary.com/spondylosis http://medical-dictionary.thefreedictionary.com/spondylosis]. Accessed on: 28 August 2011.</ref>).


Clinical:
Note:
*''Auspitz sign'' = pin-point bleeding on removal of scale.
*''Dermatophytosis'' (ring worm) is a type of dermatomycosis.
*''Koebner phenomenon'' = lesions form at site of trauma.


===Microscopic===
===Microscopic===
Features:<ref name=Ref_PCPBoD8_603>{{Ref PCPBoD8|603}}</ref>
Features:
*Acanthosis + long rete ridges - '''key feature'''.
*Microorganisms - '''key feature'''.
*Parakeratosis.
**Often hyphae (candida) - like twigs of a tree... branching.
*Dilated vessels in superficial dermis (give rise to ''Auspitz sign'').
***May be very fragmented in section ~ size of a neutrophil.
*Spongiform pustules = PMNs in stratum spinosum.
*Perivascular inflammation, esp. neutrophils.
*PMNs in parakeratotic stratum corneum (Munro microabscess).
*[[Exocytosis]] - blood cell infiltrate the epidermis.


=Other=
====Images====
==Squamous cell hyperplasia==
<gallery>
*[[AKA]] ''lichen simplex chronicus''.<ref name=Ref_PBoD1011>{{Ref PBoD8|1011}}</ref>
Image:Dermatomycosis_-_intermed_mag.jpg | Dermatomycosis - intermed. mag. (WC)
Image:Dermatomycosis_-_high_mag.jpg | Dermatomycosis - high mag. (WC)
Image:Dermatomycosis_-_gms_-_low_mag.jpg | Dermatomycosis - GMS stain - low mag. (WC)
Image:Dermatomycosis_-_gms_-_high_mag.jpg | Dermatomycosis - GMS stain - high mag. (WC)
</gallery>
www:
*[http://missinglink.ucsf.edu/lm/DermatologyGlossary/img/Dermatology%20Glossary/Glossary%20Histo%20Images/tinea_pas.jpg Dermatophytosis (ucsf.edu)].<ref>URL: [http://missinglink.ucsf.edu/lm/DermatologyGlossary/tinea.html http://missinglink.ucsf.edu/lm/DermatologyGlossary/tinea.html]. Accessed on: 25 February 2013.</ref>


===General===
===Stains===
*Variant of ''spongiotic dermatitis''.<ref name=Ref_DCHH296>{{Ref DCHH|296}}</ref>
*[[GMS stain]].
*[[PAS-D stain]].


Etiology:<ref>URL: [http://emedicine.medscape.com/article/1123423-overview http://emedicine.medscape.com/article/1123423-overview]. Accessed on: 20 August 2010.</ref>
===Sign out===
*Pruritus (itchness) -> mechanical trauma -> lichenification (thickened/leathery<ref>URL: [http://www.medterms.com/script/main/art.asp?articlekey=10131 http://www.medterms.com/script/main/art.asp?articlekey=10131]. Accessed on: 20 August 2010.</ref>.
<pre>
SKIN, BIOPSY:
- SKIN WITH SUPERFICIAL FUNGAL ORGANISMS CONSISTENT WITH CANDIDA.
- REACTIVE CHANGES OF THE EPITHELIUM.
</pre>


===Microscopic===
====Micro====
Features:<ref name=Ref_PBoD1065-6>{{Ref PBoD|1065-6}}</ref>
The sections show skin with a neutrophilic infiltrate in the superficial epidermis. PAS-D staining demonstrates fungal organisms with a morphology suggestive of candida.
*Acanthosis (epithelial thickening).  
*Hyperkeratosis.
Other features:<ref>URL: [http://emedicine.medscape.com/article/1123423-diagnosis http://emedicine.medscape.com/article/1123423-diagnosis]. Accessed on: 20 August 2010.</ref>
*Spongiosis (epidermal intercellular edema -- cells appear to have a clear halo around 'em).
*Parakeratosis = retention of nuclei in the stratum corneum.


Images:
The epithelium has parakeratosis, acanthosis and spongiosis. No mitotic activity is appreciated. The keratinocytes are moderately enlarged and have evident nucleoli.
*[http://commons.wikimedia.org/w/index.php?title=File:Lichen_simplex_chronicus_-_low_mag.jpg LSC - low mag. (WC)].
*[http://commons.wikimedia.org/w/index.php?title=File:Lichen_simplex_chronicus_-_high_mag.jpg LSC - high mag. (WC)].


=Very common=
==Cicatrix==
==Dermatophytosis==
{{Main|Dermal scar}}
===General===
*[[microorganisms|Fungal infection]] of skin.


===Microscopic===
==Fibroepithelial polyp==
Features:
{{Main|Fibroepithelial polyp}}
*Microorganisms - '''key feature'''.
**Often hyphae (candida) - like twigs of a tree... branching.
*Perivascular inflammation.
*Exocytosis - blood cell infiltrate the epidermis.


===Stains===
==Actinic keratosis==
*[[GMS]].
{{Main|Actinic keratosis}}
*[[PAS]].


==Cicatrix==
==Actinic cheilitis==
*[[AKA]] ''scar''.
===General===
===General===
*Previous surgery, biopsy, trauma.
*[[Actinic keratosis]] of the lip.<ref name=pmid3305604>{{Cite journal  | last1 = Picascia | first1 = DD. | last2 = Robinson | first2 = JK. | title = Actinic cheilitis: a review of the etiology, differential diagnosis, and treatment. | journal = J Am Acad Dermatol | volume = 17 | issue = 2 Pt 1 | pages = 255-64 | month = Aug | year = 1987 | doi =  | PMID = 3305604 }}</ref>


===Microscopic===
===Microscopic===
Features:
:See ''[[actinic keratosis]]''.
*Loss of adnexal structures.
*Dense collagen - fibers run parallel to the dermal-epidermal (DE) junction.
*Loss of dermal papilla.


Image:
===Sign out===
*[http://commons.wikimedia.org/wiki/File:ScarHistology.JPG Scar (WC)].
<pre>
LESION, LOWER LIP, BIOPSY:  
- ACTINIC CHEILITIS.
- SOLAR ELASTOSIS.
</pre>


==Fibroepithelial polyp==
====Micro====
*[[AKA]] ''acrochordon'', ''skin tag''.
The sections show skin with moderate basal nuclear hyperchromasia and atypia, and parakeratosis. The squamous epithelium has maturation to the surface. There is no inflammation at the dermal-epidermal interface. Solar elastosis is present.
===General===
*Benign.
*Older people.
*May be associated with pregnancy, diabetes, intestinal polyposis.<ref name=Ref_PCPBoD8|596>{{Ref PCPBoD8|596}}</ref>


===Gross===
==Seborrheic keratosis==
*Raised skin-coloured lesion.
{{Main|Seborrheic keratosis}}


Image:
==Pilomatricoma==
*[http://commons.wikimedia.org/wiki/File:Skintagblemish.jpg Skin tag (WC)].
{{Main|Pilomatricoma}}


===Microscopic===
==Dermatofibroma==
Features:
{{Main|Dermatofibroma}}
*On a stalk / epithelium on three sides.
*Benign epidermis.


Image:
==Ezcema==
*[http://dermatlas.med.jhmi.edu/derm/IndexDisplay.cfm?ImageID=1767547949 Fibroepithelial polyp (dermatlas.med.jhmi.edu)].<ref>URL: [http://dermatlas.med.jhmi.edu/derm/result.cfm?Diagnosis=1196583692 http://dermatlas.med.jhmi.edu/derm/result.cfm?Diagnosis=1196583692]. Accessed on: 1 September 2011.</ref>
 
==Actinic keratosis==
*AKA solar keratosis. (???)
===General===
===General===
Clinical: yellow-brown scaly, patches, sandpaper sensation.
*A nebulous thingy.
*Very common.


Risk factors:<ref name=Ref_PBoD8_1180>{{Ref PBoD8|1180}}</ref>
DDx:
*Sun exposure.
*Contact allergy.
*Immune suppression (e.g. organ transplant recipients).
*[[Drug reaction]].
*Food allergy.


===Microscopic===
===Microscopic===
Features:<ref>URL: [http://emedicine.medscape.com/article/1099775-workup#a0723 http://emedicine.medscape.com/article/1099775-workup#a0723]. Accessed on: 1 September 2011.</ref>
Features:<ref>{{Ref PBoD8|1188}}</ref>
*Epidermal nuclear atypia:
*Spongiosis (epidermal edema); keratinocytes spacing increased - '''key feature'''.
**Variation is size, shape and staining.
*+/-Interdermal vesicles.
***Nuclear enlargement - '''key feature'''.
*+/-Eosinophils (may suggest Rx reaction).
****Should involve the basal layer.
*Perivascular lymphocytes.
*Abnormal epidermal architecture:
**Pallisading. (???)
*+/-Parakeratosis.
*+/-Irregular acanthosis.


Image:
==Acne vulgaris==
*[http://commons.wikimedia.org/wiki/File:Actinic_Keratosis,_H%26E.jpg Actinic keratosis (WC)].
 
==Seborrheic keratosis==
*Abbreviated ''SK''.
===General===
===General===
*Benign.
*Extremely common - esp. among adolescents.
*Most common tumour in older people.<ref name=emed_sk2>URL: [http://emedicine.medscape.com/article/1059477-overview#a0199 http://emedicine.medscape.com/article/1059477-overview#a0199]. Accessed on: 26 August 2011.</ref>
*Very rarely seen by pathologists.
*"Large number" of SKs = paraneoplastic syndrome (''Leser–Trélat sign'').<ref name=Ref_PCPBoD8_595>{{Ref PCPBoD8|595}}</ref>


Epidemiology:
Treatments:
*Old people.
*Antibiotic (minocycline).
*Usu. in sun exposed area.<ref name=emed_sk1>URL: [http://emedicine.medscape.com/article/1059477-overview http://emedicine.medscape.com/article/1059477-overview]. Accessed on: 26 August 2011.</ref>
*Isotretinoin [[AKA]] all-trans retinoic acid (ATRA).


===Gross===
===Gross===
*"Stuck-on" appearance - raised lesion.
*Papules, pustules, nodules or cysts.
**White, black or erythematous.


Image(s):  
Images:
*[http://www.dermatlas.org/derm/IndexDisplay.cfm?ImageID=91774460 SK - gross image (dermatlas.org)].
*[http://commons.wikimedia.org/wiki/File:Blackheads.JPG Blackheads (WC)].


===Microscopic===
===Microscopic===
Features:<ref name=Ref_PCPBoD8_595>{{Ref PCPBoD8|595}}</ref>
Features:<ref>{{Ref Derm|76}}</ref>
*Raised above skin surface.
*Folliculitis:<ref name=Ref_Derm77>{{Ref Derm|77}}</ref>
*Border sharply demarcated.
**[[Neutrophil]]s around hair follicle and infiltrate into it - including the follicular canal.
*Hyperkeratosis - stratum corneum extra thick.
*Epidermal invagination ''or'' cyst at site of a hair follicle - contains:
*Horn cysts - intraepidermal collections of keratin.
**Sebum.
*Clusters of cells with brown granular material in the superficial dermis/dermoepidermal junction - pigmented melanocytes.  
**+/-Bacteria (''Propionibacterium acnes'') and inflammatory cells - typically neurophils.


Images:
Subtyped into:
*[http://commons.wikimedia.org/wiki/File:Seborrheic_keratosis_(1).jpg Seborrheic keratosis - low mag. (WC)].
#Open comedones ("blackheads") - no extension to epidermal surface.
*[http://commons.wikimedia.org/wiki/File:Seborrheic_keratosis_%282%29.jpg Seborrheic keratosis - high mag. (WC)].
#Closed comedones ("whiteheads") - to epidermal surface have wide opening.
*[http://www.dermatlas.org/derm/IndexDisplay.cfm?ImageID=-1985374774 Seborrheic keratosis - high mag. (dermatlas.org)].
*[http://www.dermatlas.org/derm/IndexDisplay.cfm?ImageID=-1880960893 Seborrheic keratosis - low mag.  (dermatlas.org)].


==Pilomatricoma==
DDx - acneiform disorder:<ref name=Ref_Derm77>{{Ref Derm|77}}</ref>
*[[AKA]] ''calcifying epithelioma of Malherbe''<ref>{{Ref Derm|387}}</ref>, [[AKA]] ''pilomatrixoma''.
*[[Rosacea]].
===General===
*Infective folliculitis.
*Benign skin tumour.
*Perioral dermatitis.
*Most common solid skin tumour of children.<ref name=emed1058965>URL: [http://emedicine.medscape.com/article/1058965-overview http://emedicine.medscape.com/article/1058965-overview]. Accessed on: 10 September 2011.</ref>
*Acne vulgaris.
*CTNNB1 gene mutation important in pathogenesis.<ref name=Ref_PCPBoD8_597>{{Ref PCPBoD8|597}}</ref>


Clinical:
Image:
*Hard nodule - calcification.
*[http://www.dermnet.com/images/Acne-Histology/picture/4069 Acne (dermnet.com)].
*+/-Painful.


Treatment:
==Solar elastosis==
*Surgical excision.<ref name=emed1058965>[http://emedicine.medscape.com/article/1058965-overview http://emedicine.medscape.com/article/1058965-overview]</ref>
*[[AKA]] ''actinic elastosis''.<ref>URL: [http://www.dermnetnz.org/dermal-infiltrative/solar-elastosis.html http://www.dermnetnz.org/dermal-infiltrative/solar-elastosis.html]. Accessed on: 27 March 2013.</ref>
===General===
*Very common.
*Caused by sun exposure - specifically UV light.<ref name=pmid20802019>{{Cite journal  | last1 = Thomas | first1 = NE. | last2 = Kricker | first2 = A. | last3 = From | first3 = L. | last4 = Busam | first4 = K. | last5 = Millikan | first5 = RC. | last6 = Ritchey | first6 = ME. | last7 = Armstrong | first7 = BK. | last8 = Lee-Taylor | first8 = J. | last9 = Marrett | first9 = LD. | title = Associations of cumulative sun exposure and phenotypic characteristics with histologic solar elastosis. | journal = Cancer Epidemiol Biomarkers Prev | volume = 19 | issue = 11 | pages = 2932-41 | month = Nov | year = 2010 | doi = 10.1158/1055-9965.EPI-10-0686 | PMID = 20802019 }}</ref>
**Severity correlated with cumulative exposure to UV light..<ref name=pmid17204514/>
*Often co-localized with skin cancers - as UV light is risk factor for skin cancers.<ref name=pmid17204514 >{{Cite journal  | last1 = Karagas | first1 = MR. | last2 = Zens | first2 = MS. | last3 = Nelson | first3 = HH. | last4 = Mabuchi | first4 = K. | last5 = Perry | first5 = AE. | last6 = Stukel | first6 = TA. | last7 = Mott | first7 = LA. | last8 = Andrew | first8 = AS. | last9 = Applebaum | first9 = KM. | title = Measures of cumulative exposure from a standardized sun exposure history questionnaire: a comparison with histologic assessment of solar skin damage. | journal = Am J Epidemiol | volume = 165 | issue = 6 | pages = 719-26 | month = Mar | year = 2007 | doi = 10.1093/aje/kwk055 | PMID = 17204514 }}</ref>
*Benign.


===Microscopic===
===Microscopic===
Features:<ref name=emed1058965dx>URL: [http://emedicine.medscape.com/article/1058965-diagnosis http://emedicine.medscape.com/article/1058965-diagnosis]. Accessed on: 10 September 2011.</ref>
Features:
*Lower dermis/subcutaneous adipose lesion; thus, usu. surrounded by connective tissue.
*Grey, spaghetti-like material in the superficial dermis.
**Sharpy demarcated island of cells.
**Calcification in 75% - with calcium staining (von Kossa).
*Cells:<ref>[http://www.bccancer.bc.ca/HPI/CE/cytotechnology/cytosleuthquiz/nongyne/ngcase02d.htm http://www.bccancer.bc.ca/HPI/CE/cytotechnology/cytosleuthquiz/nongyne/ngcase02d.htm]</ref>
**Basaloid epithelial cells - have prominent nucleoli.
**Anucleate squamous cells ("ghost cells").
**Giant cell foreign body type [[granulomas]] (form in reaction to keratin).
 
Notes:
*Keratin a prominent feature on cytology - lots of orange stuff.
 
Images:
*[http://www.bccancer.bc.ca/HPI/CE/cytotechnology/cytosleuthquiz/nongyne/ngcase02.htm Pilomatrixoma - cytology (bccancer.bc.ca)].
*[http://www.dermrounds.com/photo/1980062:Photo:431 Pilomatrixoma - histology (dermrounds.com)].
*[http://en.wikipedia.org/wiki/File:Pilomatrixoma_-_high_mag.jpg Pilomatrixoma - high mag. (WC)].
*[http://en.wikipedia.org/wiki/File:Pilomatrixoma_-_intermed_mag.jpg Pilomatrixoma - intermed. mag. (WC)].


DDx:
DDx:
*[[Epidermal inclusion cyst]].
*[[Actinic keratosis]].
 
*[[Basal cell carcinoma]].
==Dermatofibroma==
*[[Squamous cell carcinoma of the skin|Squamous cell carcinoma]].
*Abbreviated ''DF''.
===General===
*AKA ''fibrous histiocytoma''.
*Reactive process -- it is ''not'' a neoplasm.
*Usually associated with previous trauma.
**In women... usually legs.


===Microscopic===
Note:
Features:<ref name=Ref_WMSP492>{{Ref WMSP|492}}</ref>
*The DDx above is things associated with sun damaged skin.
*Prominent fibrous bundles, especially at the edge of the lesion.
*Dermal mucin (as my be seen in [[lupus erythematosus]]) is a possible mimic - but it isn't spaghetti-like and the "background" (an [[interface dermatitis]]) is different.
**Surrounded by spindle cells (fibroblasts).
***Usually thought of as fibroblasts surrounded by fibrous material ("collagen-trapping").
*Lack of adnexal structures, i.e. no sweat glands, no hair.
*+/-Epidermal changes - known as "dirty fingers":<ref>BD. 13 April 2011.</ref>
**Acanthosis (thickened epithelial layer - specifically thickened ''stratum spinosum'').
**Basal keratinocyte hyperpigmentation.


Images:
====Images====
*[http://missinglink.ucsf.edu/lm/DermatologyGlossary/dermatofibroma.html Dermatofibroma (ucsf.edu)].
<gallery>
*[http://www.pacificderm.org/newsflashcpcapril04.html DF - several images (pacificderm.org)].
Image:Solar_elastosis_-_intermed_mag.jpg | Solar elastosis - intermed. mag. (WC)
Image:Solar_elastosis_-_high_mag.jpg | Solar elastosis - high mag. (WC)
</gallery>
www:
*[http://dermpathexpert.com/id88.html Solar elastosis - several images (dermpathexpert.com)].


DDx:
===Sign out===
*[[Dermatofibrosarcoma protuberans]] (DFSP).
<pre>
*[[Neurofibroma]].
SKIN, RIGHT CHEEK, RE-EXCISION:
*[[Blue nevus]].
- DERMAL SCAR.
*[[Melanoma]].
- EXTENSIVE SOLAR ELASTOSIS.
</pre>


====Subtypes====
=====Prominent blood vessels=====
Like all common things... there are subtypes:<ref>{{Ref Sternberg5|51}}</ref>
<pre>
*Cellular.
SKIN LESION, LEFT CHEEK, BIOPSY:
*Deep penetrating.
- SKIN WITH SOLAR ELASTOSIS AND PROMINENT SMALL BLOOD VESSELS.
*Lipidized - with foamy macrophages, hemorrhage and Touton-like giant cells.
</pre>
*Epithelioid cell histiocytoma.
*Fibrotic.
*Aneurysmal - large blood filled + features of ''lipidized''.
*Granular cell dermatofibroma.
*Dermatofibroma with monster cells.


===IHC===
<pre>
Features:<ref name=pmid7694515>{{cite journal |author=Abenoza P, Lillemoe T |title=CD34 and factor XIIIa in the differential diagnosis of dermatofibroma and dermatofibrosarcoma protuberans |journal=Am J Dermatopathol |volume=15 |issue=5 |pages=429–34 |year=1993 |month=October |pmid=7694515 |doi= |url=}}</ref><ref name=pmid9129699>{{cite journal |author=Goldblum JR, Tuthill RJ |title=CD34 and factor-XIIIa immunoreactivity in dermatofibrosarcoma protuberans and dermatofibroma |journal=Am J Dermatopathol |volume=19 |issue=2 |pages=147–53 |year=1997 |month=April |pmid=9129699 |doi= |url=}}</ref>
SUPERIOR SHOULDER, LEFT, PUNCH BIOPSY:
*Factor XIIIa +ve.
- BENIGN SKIN WITH MODERATE SOLAR ELASTOSIS, PROMINENT SMALL BLOOD VESSELS AND
**Usually negative in [[DFSP]].
  SCATTERED PERIVASCULAR LYMPHOCYTES AND PLASMA CELLS.
*CD34 -ve.
- NEGATIVE FOR BASAL CELL CARCINOMA.
**Usually positive in DFSP.
- NEGATIVE FOR ACTINIC KERATOSIS.
*D2-40 +ve.<ref name=pmid20062007>{{cite journal |author=Bandarchi B, Ma L, Marginean C, Hafezi S, Zubovits J, Rasty G |title=D2-40, a novel immunohistochemical marker in differentiating dermatofibroma from dermatofibrosarcoma protuberans |journal=Mod. Pathol. |volume=23 |issue=3 |pages=434–8 |year=2010 |month=March |pmid=20062007 |doi=10.1038/modpathol.2009.176 |url=}}</ref>
</pre>
**Usually negative in DFSP.


==Ezcema==
====Micro====
===General===
The sections show hair bearing skin with solar elastosis and numerous small dilated blood vessels. The dermis is mildly fibrotic. Compact keratin is present.
*A nebulous thingy.
*Very common.


DDx:
The epidermis matures to the surface. A granular layer is present. There is no basal
*Contact allergy.
epidermal atypia. No melanocytic nests are identified. There is no palisading of the basal
*Drug reaction.
cells. Rare scattered lymphocytes are in the dermis.
*Food allergy.
 
===Microscopic===
Features:<ref>{{Ref PBoD8|1188}}</ref>
*Spongiosis (epidermal edema); keratinocytes spacing increased - '''key feature'''.
*+/-Interdermal vesicles.
*+/-Eosinophils (may suggest Rx reaction).
*Perivascular lymphocytes.


=Very common - viral=
=Very common - viral=
==Verruca vulgaris==
==Verruca vulgaris==
===General===
{{Main|Verruca vulgaris}}
*[[AKA]] common wart.
*Etiology - [[HPV]].
 
Notes:
*Related to [[condyloma acuminatum]].
 
===Microscopic===
Features:<ref>URL: [http://missinglink.ucsf.edu/lm/DermatologyGlossary/verruca_vulgaris.html http://missinglink.ucsf.edu/lm/DermatologyGlossary/verruca_vulgaris.html]. Accessed on: 14 July 2010.</ref>
*Hyperkeratosis (more keratin - thick stratum corneum).
*Hypergranulosis (thicker stratum granulosum).
*Acanthosis (thickening of the stratum spinosum).
*Rete ridges lengthened (~7-10x normal).
*Large blood vessels at the dermal-epidermal junction.
 
Memory device: there is more of everything - more s. corneum, s. granulosum, s. spinosum, longer rete ridges, more (larger) blood vessels.
 
Images:
*[http://commons.wikimedia.org/wiki/File:Verruca_vulgaris_-_very_low_mag.jpg Verruca vulgaris - very low mag. (WC)].
*[http://commons.wikimedia.org/wiki/File:Verruca_vulgaris_-_intermed_mag.jpg Verruca vulgaris - intermed mag. (WC)].


==Verruca plana==
==Verruca plana==
Line 449: Line 238:
*Viral keratohyaline.
*Viral keratohyaline.
*Koilocytes.
*Koilocytes.
*Acanthosis - yet flat surface and base.
*[[Acanthosis]] - yet flat surface and base.


Notes:
Notes:
*It differs from verruca vulgaris... (1) orthokeratosis, (2) flat surface and base.
*It differs from [[verruca vulgaris]]... (1) orthokeratosis, (2) flat surface and base.


=Less common=
=Less common=
==Dilated pore of Winer==
==Chronic folliculitis==
:''Folliculitis'' redirect here.
===General===
===General===
*Benign.
*Common.
*Looks like zit.
*Infrequently biopsied.


===Microscopic===
===Gross===
Features:<ref name=Ref_WMSP486>{{Ref WMSP|486}}</ref>
*Erythema.<ref>URL: [http://www.webmd.com/skin-problems-and-treatments/tc/folliculitis-topic-overview http://www.webmd.com/skin-problems-and-treatments/tc/folliculitis-topic-overview]. Accessed on: 7 November 2012.</ref>
*Dilated hair follicle with keratin.
*Acanthosis.
*Budding of epidermis (into dermis).
 
==Lichenoid keratosis==
===General===
*Caucasians - middle age or older.  


Clinical DDx:<ref name=Ref_Derm346>{{Ref Derm|346}}</ref>
DDx gross:
*[[BCC]], [[SCC]], melanocytic neoplasm.
*[[Melanocytic lesion]]s.


===Microscopic===
===Microscopic===
Features:<ref name=Ref_Derm347>{{Ref Derm|347}}</ref>
Features:
*Hyperkeratosis.
*Inflammation around the hair follicle - '''key feature'''.
*Parakeratosis.
**Lymphocytes - usu. predominant.
*Band of inflammatory cells at DE junction (lichenoid inflammation).
*+/-Chronic changes:
*Dead keratinocytes (Civatte bodies).
**[[Acanthosis]].
*Dermal melanophages.  
**Hyperkeratosis.
**Hypergranulosis.


DDx:
DDx:
*[[Lichen planus]] - need clinical correlation (mucosal lesions).
*[[Acne vulgaris]].
*Drug reaction.
 
*[[Cutaneous T-cell lymphoma]].
===Sign out===
*Regressed melanocytic lesion.
<pre>
SKIN LESION, UPPER ARM, BIOPSY:
- CHRONIC FOLLICULITIS WITH SECONDARY SURFACE CHANGES.
</pre>


Images:
====Micro====
*[http://www.dermpathexpert.com/id57.html Lichenoid keratosis (dermpathexpert.com)].
The sections show hair-bearing skin with abundant lymphocytes around and within the hair follicle wall.  


==Granuloma annulare==
The non-hair follicle epidermis has acanthosis, hypergranulosis and compact hyperkeratosis.  There is no inflammatory cell infiltrate in the non-hair follicle epidermis or at the non-hair follicle interface.
===General===
*Benign and self-limited condition.
*Etiology unknown - may be assoc. with trauma.<ref name=Ref_Derm51>{{Ref Derm|51}}</ref>


===Microscopic===
There are no granulomas.
Features:<ref name=Ref_WMSP478>{{Ref WMSP|478}}</ref>
*Dermal palisading [[granuloma]] around:
**Necrotic collagen - '''key feature'''.
***Nuclei "missing" - have undergone karyolysis.
**Mucin.
***Loose/pale, paucicellular, eosinophilic.
*Chronic inflammatory cells.


Notes:
==Clear cell acanthoma==
#There may be multiple small foci with intervening normal dermis.<ref name=Ref_Derm51>{{Ref Derm|51}}</ref>
{{Main|Clear cell acanthoma}}
#Granuloma annulare can be subclassified into ''subcutaneous'' and ''interstitial''.
#Histomorphologically similar to ''[[Rheumatoid nodule]].


DDx:
==Chondrodermatitis nodularis chronica helicis==
*Necrobiosis lipoidica - little mucin, no normal dermis between foci.<ref name=Ref_Derm51>{{Ref Derm|51}}</ref>
*[[AKA]] ''chondrodermatitis nodularis helicis''.
*[[Rheumatoid nodule]].
*Abbreviated ''CNCH''.
*[[AKA]] ''Winkler disease''.<ref>URL: [http://www.head-face-med.com/content/4/1/2 http://www.head-face-med.com/content/4/1/2]. Accessed on: 16 January 2014.</ref>
{{Main|Chondrodermatitis nodularis chronica helicis}}


Images:
==Cutaneous calcinosis==
*[http://www.dermaamin.com/site/histopathology-of-the-skin/61-i/1813-interstitial-granuloma-annulare-.html Granuloma annulare (dermaamin.com)].
*[[AKA]] ''calcinosis cutis''.
{{Main|Cutaneous calcinosis}}


==Keloid==
==Dilated pore of Winer==
===General===
===General===
*Sites of previous trauma/surgery, esp. in dark skinned individuals.<ref name=Ref_WMSP492>{{Ref WMSP|492}}</ref>
*Benign.
*Looks like a zit.


===Microscopic===
===Microscopic===
Features:<ref name=Ref_WMSP492>{{Ref WMSP|492}}</ref>
Features:<ref name=Ref_WMSP486>{{Ref WMSP|486}}</ref>
*Thick collagen bundles - surrounded by paler staining fibroblasts - '''key feature'''.
*Dilated hair follicle with keratin.
*Lesion replaces adnexal structures, e.g. hair, sweat glands.
*[[Acanthosis]].
*Budding of epidermis (into dermis).


Images:
DDx:
*[http://missinglink.ucsf.edu/lm/DermatologyGlossary/keloids.html Keloids (ucsf.edu)].
*[[Pilar sheath acanthoma]].
 
==Angiofibroma==
:See also: ''[[nasopharyngeal angiofibroma]]''.
===General===
*May be seen in the context of [[tuberous sclerosis]] - esp. "butterfly area of the face".<ref name=Ref_WMSP492>{{Ref WMSP|492}}</ref>
 
Clinical:
*Firm, dome-shaped, flesh coloured.
 
===Microscopic===
Features:<ref name=Ref_WMSP492>{{Ref WMSP|492}}</ref>
*Dome-shaped.
*Fibrotic dermis.
**Enlarged fibroblasts.
*Dilated small vessels.


Image:
Image:
*[http://www.drdittmar.lu/images/sce/angiofibroma-s.jpg Angiofibroma (drdittmar.lu)].<ref>URL: [http://www.drdittmar.lu/Services.aspx http://www.drdittmar.lu/Services.aspx]. Accessed on: 1 September 2011.</ref>
*[http://dermpathexpert.com/id90.html Dilated pore of Winer (dermpathexpert.com)].


==Molluscum contagiosum==
==Lichenoid keratosis==
===General===
*[[AKA]] ''lichen planus-like keratosis''.
*Etiology: caused by ''molluscum contagiosum virus''.
{{Main|Lichenoid keratosis}}


===Microscopic===
==Granuloma annulare==
Features:
{{Main|Granuloma annulare}}
*A suprabasilar epidermal lesion consisting of "molluscum bodies", i.e. ''molluscum bodies'' are found above the stratum basale.<ref>[http://www.missionforvisionusa.org/anatomy/2006/08/what-is-molluscum-contagiosum.html http://www.missionforvisionusa.org/anatomy/2006/08/what-is-molluscum-contagiosum.html]</ref>
*Molluscum bodies - '''key feature''':
**Large cells with abundant granular eosinophilic cytoplasm.
**Small peripheral nucleus.


Image(s):
==Necrobiosis lipoidica==
*[http://commons.wikimedia.org/wiki/File:Molluscum_contagiosum_high_mag.jpg Molluscum contagiosum - high mag. (WC)].
{{Main|Necrobiosis lipoidica}}
*[http://commons.wikimedia.org/wiki/File:Molluscum_contagiosum_low_mag.jpg Molluscum contagiosum - low magnification (WC)].


Notes:
==Keloid==
*Molluscum bodies very vaguely resemble ''[[signet ring cell]]s'' -- but:
{{Main|Keloid}}
**Cytoplasm eosinophilic and granular.
**Nucleus usually smaller than in signet ring cell.
**''Molluscum bodies'' are only the epidermis - an uncommon place to find SRCs without finding them elsewhere.
*The granular eosinophilic cytoplasm represents accumulated virons.


==Syringoma==
==Angiofibroma==
===General===
:See also: ''[[nasopharyngeal angiofibroma]]''.
*Benign sweat duct tumour.
:Should '''not''' be confused with ''[[angiokeratoma]]''.
*Eccrine differentiation.
{{Main|Angiofibroma}}
*Usually close to lower eyelid.<ref>{{Ref PBoD8|1177}}</ref>
 
===Microscopic===
Features:<ref>URL: [http://emedicine.medscape.com/article/1059871-diagnosis http://emedicine.medscape.com/article/1059871-diagnosis]. Accessed on: 12 May 2010.</ref>
*Proliferation of benign ducts with lined by a bilayer (as in normal sweat ducts) with abnormal architecture:
**Tadpole like appearing ducts.
 
Image:
*[http://www.flickr.com/photos/euthman/2329061316/ Syringoma (flickr.com)].


==Chondroid syringoma==
==Benign fibrous papule==
*Used to be called ''mixed tumour of skin''.<ref name=pmid19693940>{{Cite journal  | last1 = Kumar | first1 = B. | title = Chondroid syringoma diagnosed by fine needle aspiration cytology. | journal = Diagn Cytopathol | volume = 38 | issue = 1 | pages = 38-40 | month = Jan | year = 2010 | doi = 10.1002/dc.21159 | PMID = 19693940 }}</ref>
*[[AKA]] ''fibrous papule''.


===General===
===General===
*Mixed apocrine & eccrine tumour of skin, usu. in the head & neck<ref name=pmid19693940/>, esp. nose and cheek.<ref name=pmid19633639/>
*An ''[[angiofibroma]]'' on the face that is solitary.<ref name=Ref_Derm505>{{Ref Derm|505}}</ref><ref name=pmid18032900>{{Cite journal  | last1 = Jacyk | first1 = WK. | last2 = Rütten | first2 = A. | last3 = Requena | first3 = L. | title = Fibrous papule of the face with granular cells. | journal = Dermatology | volume = 216 | issue = 1 | pages = 56-9 | month =  | year = 2008 | doi = 10.1159/000109359 | PMID = 18032900 }}</ref>
*May be in major and minor salivary glands.<ref name=pmid19633639>{{Cite journal  | last1 = Rauso | first1 = R. | last2 = Santagata | first2 = M. | last3 = Tartaro | first3 = G. | last4 = Filipi | first4 = M. | last5 = Colella | first5 = G. | title = Chondroid syringoma: a rare tumor of orofacial region. | journal = Minerva Stomatol | volume = 58 | issue = 7-8 | pages = 383-8 | month =  | year = | doi = | PMID = 19633639 }}</ref>


===Microscopic===
===Gross===
Features:
*Solitary lesion of the face - '''important'''.<ref name=Ref_Derm505>{{Ref Derm|505}}</ref>
*Mix tumour with:<ref name=pmid19693940/>
**Usually on the nose.<ref name=pmid18032900/>
*#Epithelial component:
*#*Nests of cells with:
*#**Moderate dull eosinophilic cytoplasm.
*#**Round/ovoid nuclei with nucleoli.
*#Mesenchymal component:
*#*Chondromyxoid stroma.
 
==Dermal cylindroma==
===General===
*Benign skin lesion.
*Should not be confused with ''cylindroma'' ([[adenoid cystic carcinoma]]).


===Microscopic===
===Microscopic===
Features:
Features:<ref name=Ref_WMSP492>{{Ref WMSP|492}}</ref>
*Nests of cells that are surrounded by hyaline (i.e. glassy, eosinophilic, acellular) material.  
*Dome-shaped.
*Fibrotic dermis.
**Enlarged fibroblasts.
*Dilated small vessels.
*+/-Multinucleated stromal cells.<ref name=pmid543528>{{Cite journal  | last1 = Ragaz | first1 = A. | last2 = Berezowsky | first2 = V. | title = Fibrous papule of the face. A study of five cases by electron microscopy. | journal = Am J Dermatopathol | volume = 1 | issue = 4 | pages = 353-6 | month =  | year = 1979 | doi =  | PMID = 543528 }}</ref>
*+/-Stellate cells.<ref name=pmid543528/>


DDx:
DDx:
*[[Eccrine spiradenoma]].
*[[Angiofibroma]] - not solitary or not on the nose.


Images:
Note:
*[http://commons.wikimedia.org/wiki/File:Dermal_cylindroma_intermed_mag.jpg Dermal cylindroma (WC)].
*Several variants exist.<ref name=pmid18032900>{{Cite journal  | last1 = Jacyk | first1 = WK. | last2 = Rütten | first2 = A. | last3 = Requena | first3 = L. | title = Fibrous papule of the face with granular cells. | journal = Dermatology | volume = 216 | issue = 1 | pages = 56-9 | month =  | year = 2008 | doi = 10.1159/000109359 | PMID = 18032900 }}</ref>
*[http://commons.wikimedia.org/wiki/File:Dermal_cylindroma_intermed_mag_deep.jpg Dermal cylindroma - high mag. (WC)].


==Keratoacanthoma==
===Images===
*Abbreviated ''KA''.
*[http://www.dermaamin.com/site/histopathology-of-the-skin/58-f/1739-fibrous-papule-angiofibroma-.html Fibrous papule (dermaamin.com)].
*Generally considered to be benign.
**Rare reports of metastases suggesting it may be a form of squamous cell carcinoma.<ref>{{cite journal |author=Mandrell JC, Santa Cruz D |title=Keratoacanthoma: hyperplasia, benign neoplasm, or a type of squamous cell carcinoma? |journal=Semin Diagn Pathol |volume=26 |issue=3 |pages=150–63 |year=2009 |month=August |pmid=20043514 |doi= |url=}}</ref>


===Clinical===
===Sign out===
*May grow rapidly (weeks or months) then involute.
<pre>
*Main DDx is [[squamous cell carcinoma]].
SKIN LESION, CHIN, BIOPSY:
*Exophytic lesion, well-circumscribed.
- BENIGN FIBROUS PAPULE.
</pre>


===Microscopic===
==Molluscum contagiosum==
Features:<ref>{{Ref Klatt|378}}</ref>
{{Main|Molluscum contagiosum}}
*Expansion of stratum spinosum - pushing tongue-like downward growth of epidermis into the dermis.
*Keratin collection (keratin plug) at the center of lesion-superficial aspect.
*Cells have glassy pink cytoplasm.
*Minimal/no nuclear atypia.
 
Image:
*[http://commons.wikimedia.org/wiki/File:Skin_keratoacanthoma_whole_slide.jpg Keratocanthoma (WC).]


==Superficial dermal infiltrates==
==Superficial dermal infiltrates==
Discussed in detail by Alsaad and Ghazarian.<ref name=pmid16311340>{{Cite journal  | last1 = Alsaad | first1 = KO. | last2 = Ghazarian | first2 = D. | title = My approach to superficial inflammatory dermatoses. | journal = J Clin Pathol | volume = 58 | issue = 12 | pages = 1233-41 | month = Dec | year = 2005 | doi = 10.1136/jcp.2005.027151 | PMID = 16311340 }}</ref>
Discussed in detail by Alsaad and Ghazarian.<ref name=pmid16311340>{{Cite journal  | last1 = Alsaad | first1 = KO. | last2 = Ghazarian | first2 = D. | title = My approach to superficial inflammatory dermatoses. | journal = J Clin Pathol | volume = 58 | issue = 12 | pages = 1233-41 | month = Dec | year = 2005 | doi = 10.1136/jcp.2005.027151 | PMID = 16311340 }}</ref>


===Dermal perivascular lymphoeosinophilic infiltration (DPLI)===
===Dermal perivascular lymphoeosinophilic infiltration===  
*Microscopic appearance is just what it is called:
*Abbreviated ''DPLI''.
**Lymphocytes and eosinophils around the vessels in the superficial dermis.
 
Microscopic appearance is just what it is called:
*Lymphocytes and eosinophils around the vessels in the superficial dermis.


DDx:<ref name=pmid16311340/>
DDx:<ref name=pmid16311340/>
*Insect bite - classically wedge-shaped.<ref name=Ref_PBoD1269>{{Ref PBoD|1269}}</ref>
*Insect bite - classically wedge-shaped.<ref name=Ref_PBoD1269>{{Ref PBoD|1269}}</ref>
*Drug reactions.
*[[Drug reaction]].
*Urticarial reactions.
*Urticarial reaction.
*Prevesicular early stage of [[bullous pemphigoid]].
*Prevesicular early stage of [[bullous pemphigoid]].
*[[HIV]] related dermatoses.
*[[HIV]] related dermatoses.
Line 664: Line 397:


==Mastocytosis==
==Mastocytosis==
===General===
{{Main|Mastocytosis}}
*Abundance of [[mast cell]]s.
 
Classification:<ref name=pmid21083038>{{Cite journal  | last1 = Arock | first1 = M. | last2 = Valent | first2 = P. | title = Pathogenesis, classification and treatment of mastocytosis: state of the art in 2010 and future perspectives. | journal = Expert Rev Hematol | volume = 3 | issue = 4 | pages = 497-516 | month = Aug | year = 2010 | doi = 10.1586/ehm.10.42 | PMID = 21083038 }}</ref>
#Cutaneous (only) - usually children.
#*Urticaria pigmentosa.
#*Others.
#Systemic - usually adults.
#*Indolent subvariant.
#*Aggressive subvariant.
#*Leukemic subvariant.
 
===Microscopic===
Features:<ref name=Ref_PBoD8|1185>{{Ref PBoD8|1185}}</ref>
*Cells in the superficial/mid dermis that are:
**Lymphocyte-like with more cytoplasm that is granular.
***Cells may have spindled or stellate morphology.
***Tend to be more abundant around vessels.
*+/-Eosinophils (common).
*+/-Edema - often prominent; gives cells a white halo.
 
Notes:
*Lymphocyte vs. mast cell:
**Lymphocytes = round; mast cells = ovoid.
 
Images:
*[http://www.jameswpattersonmd.com/case_studies/index.cfm?CFID=387434 Mastocytosis - low res. (jameswpattersonmd.com)].
 
===Stains===
*[[Toluidine blue stain|Toluidine blue]] -- highlights the granules.
 
===IHC===
*CD117 +ve.
*Tryptase +ve.<ref name=pmid21866466>{{Cite journal  | last1 = Rudzki | first1 = Z. | last2 = Sotlar | first2 = K. | last3 = Kudela | first3 = A. | last4 = Starzak-Gwóźdź | first4 = J. | last5 = Horny | first5 = HP. | title = Systemic mastocytosis (SM) and associated malignant bone marrow histiocytosis - a hitherto undescribed form of SM-AHNMD. | journal = Pol J Pathol | volume = 62 | issue = 2 | pages = 101-4 | month =  | year = 2011 | doi =  | PMID = 21866466 }}
</ref>


==Ichthyosis==
==Ichthyosis==
Line 705: Line 404:
*Usu. inherited... thus a pediatric condition.
*Usu. inherited... thus a pediatric condition.


Clinical:
===Gross===
*Fish scale-like appearance.
*Fish scale-like appearance.
Image:
*[http://commons.wikimedia.org/wiki/File:Ichthyosis_1.jpg Ichtyosis (WC)].


===Microscopic===
===Microscopic===
Line 713: Line 415:


==Palmar fibromatosis==
==Palmar fibromatosis==
===General===
*[[AKA]] ''Dupuytren's contracture''.
*[[AKA]] Dupuytren's contracture.
*[[AKA]] ''Dupuytren disease''.
 
{{Main|Palmar fibromatosis}}
Clinical:<ref>URL: [http://www.humpath.com/palmar-fibromatosis http://www.humpath.com/palmar-fibromatosis]. Accessed on: 6 January 2011.</ref>
*Usually older 60-70s.
*Male > female.
*Associated with:
**Alcohol abuse.
*May be familial.
 
===Microscopic===
Features:<ref>URL: [http://surgpathcriteria.stanford.edu/softfib/plantar_fibromatosis/printable.html]. Accessed on: 6 January 2011.</ref>
*Bland spindle cells in dense collagen.
**No nuclear atypia.
*Giant cells.
*+/-Mitotic figures.
 
Images:
*[http://www.biomedsearch.com/attachments/display/00/16/69/68/16696857/1479-5876-4-21-2.jpg Palmer fibromatosis (biomedsearch.com)].<ref name=pmid16696857>{{cite journal |author=Wang L, Zhu H |title=Clonal analysis of palmar fibromatosis: a study whether palmar fibromatosis is a real tumor |journal=J Transl Med |volume=4 |issue= |pages=21 |year=2006 |pmid=16696857 |pmc=1488873 |doi=10.1186/1479-5876-4-21 |url=http://www.biomedsearch.com/nih/Clonal-analysis-palmar-fibromatosis-study/16696857.html}}</ref>


==Angiomyoma==
==Angiomyoma==
Line 750: Line 436:


==Angiokeratoma==
==Angiokeratoma==
===General===
{{Main|Angiokeratoma}}
*Rare.
*May be seen in the context of [[Fabry disease]].<ref name=pmid16403380/>
 
Notes:
*Shouldn't be confused with ''[[angiofibroma]]'' which is associated [[tuberous sclerosis]].
 
===Microscopic===
Features:<ref name=pmid16403380>{{Cite journal  | last1 = Karen | first1 = JK. | last2 = Hale | first2 = EK. | last3 = Ma | first3 = L. | title = Angiokeratoma corporis diffusum (Fabry disease). | journal = Dermatol Online J | volume = 11 | issue = 4 | pages = 8 | month =  | year = 2005 | doi =  | PMID = 16403380 }}</ref>
*Ectatic superficial dermal vessels.
*Overlying hyperkeratosis
 
Others: (???)
*Irregular acanthosis.
*Longer rete ridges.
 
Images:
*[[WC]]:
**[http://commons.wikimedia.org/wiki/File:Angiokeratoma_-_low_mag.jpg Angiokeratoma - low mag. (WC)].
**[http://commons.wikimedia.org/wiki/File:Angiokeratoma_-_intermed_mag.jpg Angiokeratoma - intermed. mag. (WC)].
*www:
**[http://www.pathologyoutlines.com/images/skintumorangiokerat1.jpg Angiokeratoma (pathologyoutlines.com)].
 
DDx:
*[[Venous lake]].


==Inverted follicular keratosis==
==Inverted follicular keratosis==
*Abbreviated ''IFK''.<ref name=pmid11411260>{{Cite journal  | last1 = Shih | first1 = CC. | last2 = Yu | first2 = HS. | last3 = Tung | first3 = YC. | last4 = Tsai | first4 = KB. | last5 = Cheng | first5 = ST. | title = Inverted follicular keratosis. | journal = Kaohsiung J Med Sci | volume = 17 | issue = 1 | pages = 50-4 | month = Jan | year = 2001 | doi =  | PMID = 11411260 }}</ref>
===General===
===General===
*Benign skin lesion.
*Benign skin lesion.
*Central face - middle age.<ref name=Ref_Derm387>{{Ref Derm|387}}</ref>
*Central face - middle age.<ref name=Ref_Derm387>{{Ref Derm|387}}</ref>
*Uncommon.
*Uncommon.
*May be considered a variant of ''[[seborrheic keratosis]]'' that is predominantly endophytic.<ref name=Ref_Derm341>{{Ref Derm|341}}</ref>


Clinical DDx:<ref name=Ref_Derm387>{{Ref Derm|387}}</ref><ref>URL: [http://www.ncbi.nlm.nih.gov/pmc/articles/PMC475744/ http://www.ncbi.nlm.nih.gov/pmc/articles/PMC475744/]. Accessed on: 11 May 2010.</ref>
Clinical DDx:<ref name=Ref_Derm387>{{Ref Derm|387}}</ref><ref>URL: [http://www.ncbi.nlm.nih.gov/pmc/articles/PMC475744/ http://www.ncbi.nlm.nih.gov/pmc/articles/PMC475744/]. Accessed on: 11 May 2010.</ref>
Line 793: Line 457:


DDx:
DDx:
*[[Squamous cell carcinoma]].
*[[Squamous cell carcinoma of the skin]].
*[[Trichilemmoma]].
*[[Trichilemmoma]].
*[[Seborrheic keratosis]] - has an exophytic component.


Images:
Images:
*[http://www.flickr.com/photos/euthman/3059309003/ Inverted follicular keratosis - low mag. (flickr.com)].
*[http://www.flickr.com/photos/euthman/3059309003/ Inverted follicular keratosis - low mag. (flickr.com)].
*[http://www.flickr.com/photos/euthman/3060145702/ Inverted follicular keratosis - high mag. (flickr.com)].
*[http://www.flickr.com/photos/euthman/3060145702/ Inverted follicular keratosis - high mag. (flickr.com)].
*[http://mckeedermpath.com/SPOT%20DIAGNOSIS%20CASE%20474.html Inverted follicular keratosis - several images (mckeedermpath.com)].
===Sign out===
<pre>
SKIN LESION, FACE, BIOPSY:
- INVERTED FOLLICULAR KERATOSIS.
</pre>
====Micro====
The sections show skin with acanthosis, pseudohorn cysts, and focal basal epidermal pigmentation.  There is no basal nuclear atypia, no mitoses and there are no melanocytic nests.  There is minimal dermal inflammation.  There is no apparent solar elastosis.
==Focal cutaneous mucinosis==
===General===
*Benign.
*May be associated with systemic disease.<ref>{{Cite journal  | last1 = Gandhi | first1 = V. | last2 = Dogra | first2 = D. | last3 = Pandhi | first3 = RK. | title = Cutaneous focal mucinosis. | journal = Indian J Dermatol Venereol Leprol | volume = 62 | issue = 4 | pages = 260-1 | month =  | year =  | doi =  | PMID = 20948074 }}</ref>
===Microscopic===
Features:
*Light blue whispy material in the dermis - '''key feature'''.
DDx:
*Dermal edema.
*[[Digital mucous cyst]].


==Panniculitis==
==Panniculitis==
Line 812: Line 500:


=Rare=
=Rare=
==Necrotizing fasciitis==
:'''''Not''' to be confused with [[nodular fasciitis]]''.
*[[AKA]] ''flesh-eating disease''.
{{Main|Necrotizing fasciitis}}
==Porokeratosis==
==Porokeratosis==
===General===
{{Main|Porokeratosis}}
*Genetic.
*Several subtypes.
 
Notes:
*Not the same as ''punctate porokeratotic keratoderma''.<ref name=pmid20137755>{{Cite journal  | last1 = Alikhan | first1 = A. | last2 = Burns | first2 = T. | last3 = Zargari | first3 = O. | title = Punctate porokeratotic keratoderma. | journal = Dermatol Online J | volume = 16 | issue = 1 | pages = 13 | month =  | year = 2010 | doi =  | PMID = 20137755 | URL = http://dermatology.cdlib.org/1601/case_presentations/ppk/alikhan.html }}</ref>
 
===Microscopic===
Features:
*Cornoid lamella (pathognomonic) - '''key feature''':
**Compact keratosis over a hair follicle.
*+/-Rete ridge loss.


==Nevus sebaceous==
==Nevus sebaceous==
*[[AKA]] ''nevus sebaceous of Jadassohn''.
*[[AKA]] ''nevus sebaceous of Jadassohn''.
===General===
{{Main|Nevus sebaceous}}
*Congenital.
*Face or scalp.


===Microscopic===
==Nevus lipomatosus superficialis==
Features:
*Abbreviated ''NLS''.
*Abundant sebaceous glands.
*[[AKA]] ''nevus lipomatosus cutaneous superficialis'', abbreviated ''NLCS''.
*[[AKA]] ''nevus lipomatosus''.<ref name=pmid15677959>{{Cite journal  | last1 = Kaw | first1 = P. | last2 = Carlson | first2 = A. | last3 = Meyer | first3 = DR. | title = Nevus lipomatosus (pedunculated lipofibroma) of the eyelid. | journal = Ophthal Plast Reconstr Surg | volume = 21 | issue = 1 | pages = 74-6 | month = Jan | year = 2005 | doi =  | PMID = 15677959 }}</ref>
{{Main|Nevus lipomatosus superficialis}}


=Bullous disease=
=Bullous disease=

Latest revision as of 17:59, 23 April 2024

Non-malignant skin disease is relatively common. The pathology may or may not be specific. Some diseases require clinical information to diagnose.

An introduction to dermatopathology is in the dermatopathology article. Nevi (moles) and other melanocytic lesions are dealt with in the article melanocytic lesions. Inflammatory skin conditions are dealt with in inflammatory skin disorders.

Other

Lichen simplex chronicus

Prurigo nodularis

  • Abbreviated PN.
  • AKA chronic prurigo and picker nodule.[1]

General

Gross

  • Dome-shaped/raised - papular (<1 cm) or nodular (>1 cm).[2]

Microscopic

DDx:

Sign out

SKIN LESION, LEFT CHIN, BIOPSY: 
- PRURIGO NODULARIS.

Micro

The sections show a raised lesion with compact hyperkeratosis and irregular acanthosis. Spongiosis is seen focally. There is minimal hypergranulosis.

There is no thinning of the suprapapillary plate and no dilated superficial blood vessels. There is no interface activity.

Very common

Dermatomycosis

Dermatophytosis redirects here.

General

Note:

  • Dermatophytosis (ring worm) is a type of dermatomycosis.

Microscopic

Features:

  • Microorganisms - key feature.
    • Often hyphae (candida) - like twigs of a tree... branching.
      • May be very fragmented in section ~ size of a neutrophil.
  • Perivascular inflammation, esp. neutrophils.
  • Exocytosis - blood cell infiltrate the epidermis.

Images

www:

Stains

Sign out

SKIN, BIOPSY:
- SKIN WITH SUPERFICIAL FUNGAL ORGANISMS CONSISTENT WITH CANDIDA.
- REACTIVE CHANGES OF THE EPITHELIUM.

Micro

The sections show skin with a neutrophilic infiltrate in the superficial epidermis. PAS-D staining demonstrates fungal organisms with a morphology suggestive of candida.

The epithelium has parakeratosis, acanthosis and spongiosis. No mitotic activity is appreciated. The keratinocytes are moderately enlarged and have evident nucleoli.

Cicatrix

Fibroepithelial polyp

Actinic keratosis

Actinic cheilitis

General

Microscopic

See actinic keratosis.

Sign out

LESION, LOWER LIP, BIOPSY: 
- ACTINIC CHEILITIS.
- SOLAR ELASTOSIS.

Micro

The sections show skin with moderate basal nuclear hyperchromasia and atypia, and parakeratosis. The squamous epithelium has maturation to the surface. There is no inflammation at the dermal-epidermal interface. Solar elastosis is present.

Seborrheic keratosis

Pilomatricoma

Dermatofibroma

Ezcema

General

  • A nebulous thingy.
  • Very common.

DDx:

Microscopic

Features:[5]

  • Spongiosis (epidermal edema); keratinocytes spacing increased - key feature.
  • +/-Interdermal vesicles.
  • +/-Eosinophils (may suggest Rx reaction).
  • Perivascular lymphocytes.

Acne vulgaris

General

  • Extremely common - esp. among adolescents.
  • Very rarely seen by pathologists.

Treatments:

  • Antibiotic (minocycline).
  • Isotretinoin AKA all-trans retinoic acid (ATRA).

Gross

  • Papules, pustules, nodules or cysts.
    • White, black or erythematous.

Images:

Microscopic

Features:[6]

  • Folliculitis:[7]
    • Neutrophils around hair follicle and infiltrate into it - including the follicular canal.
  • Epidermal invagination or cyst at site of a hair follicle - contains:
    • Sebum.
    • +/-Bacteria (Propionibacterium acnes) and inflammatory cells - typically neurophils.

Subtyped into:

  1. Open comedones ("blackheads") - no extension to epidermal surface.
  2. Closed comedones ("whiteheads") - to epidermal surface have wide opening.

DDx - acneiform disorder:[7]

  • Rosacea.
  • Infective folliculitis.
  • Perioral dermatitis.
  • Acne vulgaris.

Image:

Solar elastosis

General

  • Very common.
  • Caused by sun exposure - specifically UV light.[9]
    • Severity correlated with cumulative exposure to UV light..[10]
  • Often co-localized with skin cancers - as UV light is risk factor for skin cancers.[10]
  • Benign.

Microscopic

Features:

  • Grey, spaghetti-like material in the superficial dermis.

DDx:

Note:

  • The DDx above is things associated with sun damaged skin.
  • Dermal mucin (as my be seen in lupus erythematosus) is a possible mimic - but it isn't spaghetti-like and the "background" (an interface dermatitis) is different.

Images

www:

Sign out

SKIN, RIGHT CHEEK, RE-EXCISION:
- DERMAL SCAR.
- EXTENSIVE SOLAR ELASTOSIS.
Prominent blood vessels
SKIN LESION, LEFT CHEEK, BIOPSY:
- SKIN WITH SOLAR ELASTOSIS AND PROMINENT SMALL BLOOD VESSELS.
SUPERIOR SHOULDER, LEFT, PUNCH BIOPSY:
- BENIGN SKIN WITH MODERATE SOLAR ELASTOSIS, PROMINENT SMALL BLOOD VESSELS AND
  SCATTERED PERIVASCULAR LYMPHOCYTES AND PLASMA CELLS.
- NEGATIVE FOR BASAL CELL CARCINOMA.
- NEGATIVE FOR ACTINIC KERATOSIS.

Micro

The sections show hair bearing skin with solar elastosis and numerous small dilated blood vessels. The dermis is mildly fibrotic. Compact keratin is present.

The epidermis matures to the surface. A granular layer is present. There is no basal epidermal atypia. No melanocytic nests are identified. There is no palisading of the basal cells. Rare scattered lymphocytes are in the dermis.

Very common - viral

Verruca vulgaris

Verruca plana

General

  • Common.
  • Usu. hands and face.[11]

Microscopic

Features:[11]

  • Orthokeratosis with basketweave pattern.
  • Hypergranulosis.
  • Viral keratohyaline.
  • Koilocytes.
  • Acanthosis - yet flat surface and base.

Notes:

  • It differs from verruca vulgaris... (1) orthokeratosis, (2) flat surface and base.

Less common

Chronic folliculitis

Folliculitis redirect here.

General

  • Common.
  • Infrequently biopsied.

Gross

DDx gross:

Microscopic

Features:

  • Inflammation around the hair follicle - key feature.
    • Lymphocytes - usu. predominant.
  • +/-Chronic changes:

DDx:

Sign out

SKIN LESION, UPPER ARM, BIOPSY:
- CHRONIC FOLLICULITIS WITH SECONDARY SURFACE CHANGES.

Micro

The sections show hair-bearing skin with abundant lymphocytes around and within the hair follicle wall.

The non-hair follicle epidermis has acanthosis, hypergranulosis and compact hyperkeratosis. There is no inflammatory cell infiltrate in the non-hair follicle epidermis or at the non-hair follicle interface.

There are no granulomas.

Clear cell acanthoma

Chondrodermatitis nodularis chronica helicis

  • AKA chondrodermatitis nodularis helicis.
  • Abbreviated CNCH.
  • AKA Winkler disease.[13]

Cutaneous calcinosis

  • AKA calcinosis cutis.

Dilated pore of Winer

General

  • Benign.
  • Looks like a zit.

Microscopic

Features:[14]

  • Dilated hair follicle with keratin.
  • Acanthosis.
  • Budding of epidermis (into dermis).

DDx:

Image:

Lichenoid keratosis

  • AKA lichen planus-like keratosis.

Granuloma annulare

Necrobiosis lipoidica

Keloid

Angiofibroma

See also: nasopharyngeal angiofibroma.
Should not be confused with angiokeratoma.

Benign fibrous papule

  • AKA fibrous papule.

General

Gross

  • Solitary lesion of the face - important.[15]
    • Usually on the nose.[16]

Microscopic

Features:[17]

  • Dome-shaped.
  • Fibrotic dermis.
    • Enlarged fibroblasts.
  • Dilated small vessels.
  • +/-Multinucleated stromal cells.[18]
  • +/-Stellate cells.[18]

DDx:

Note:

  • Several variants exist.[16]

Images

Sign out

SKIN LESION, CHIN, BIOPSY:
- BENIGN FIBROUS PAPULE.

Molluscum contagiosum

Superficial dermal infiltrates

Discussed in detail by Alsaad and Ghazarian.[19]

Dermal perivascular lymphoeosinophilic infiltration

  • Abbreviated DPLI.

Microscopic appearance is just what it is called:

  • Lymphocytes and eosinophils around the vessels in the superficial dermis.

DDx:[19]

Notes:

  • May superficially resemble cutaneous lymphoma.[20]

Images:

Congenital dermal melanocytosis

  • AKA Mongolian spots.
  • Classically seen in asian children.

Gross:

  • Brown or blue-grey patch in the lumbosacral area.

Mastocytosis

Ichthyosis

General

  • Comes in different flavours.
  • Usu. inherited... thus a pediatric condition.

Gross

  • Fish scale-like appearance.

Image:

Microscopic

Features:[21]

  • Thick stratum corneum without basket-weave pattern.

Palmar fibromatosis

  • AKA Dupuytren's contracture.
  • AKA Dupuytren disease.

Angiomyoma

General

  • Benign.
  • Female > male.[22]

Microscopic

Features:

  • Well-circumscribed lesion with fascicular architecture.
  • Spindle cells/epithelioid cell with moderate eosinophilic (pink) cytoplasm.
  • Thick-walled blood vessels. (???)

Images:

Angiokeratoma

Inverted follicular keratosis

  • Abbreviated IFK.[23]

General

  • Benign skin lesion.
  • Central face - middle age.[24]
  • Uncommon.
  • May be considered a variant of seborrheic keratosis that is predominantly endophytic.[25]

Clinical DDx:[24][26]

Microscopic

Features:[24]

  • Keratinocyte of cytologically benign proliferation.
  • "Squamous eddies" (whorls of keratin).
  • Coarse keratohyaline granules.

DDx:

Images:

Sign out

SKIN LESION, FACE, BIOPSY:
- INVERTED FOLLICULAR KERATOSIS.

Micro

The sections show skin with acanthosis, pseudohorn cysts, and focal basal epidermal pigmentation. There is no basal nuclear atypia, no mitoses and there are no melanocytic nests. There is minimal dermal inflammation. There is no apparent solar elastosis.

Focal cutaneous mucinosis

General

  • Benign.
  • May be associated with systemic disease.[27]

Microscopic

Features:

  • Light blue whispy material in the dermis - key feature.

DDx:

Panniculitis

This is dealt with in the panniculitis article.

DDx for panniculitis:

Rare

Necrotizing fasciitis

Not to be confused with nodular fasciitis.
  • AKA flesh-eating disease.

Porokeratosis

Nevus sebaceous

  • AKA nevus sebaceous of Jadassohn.

Nevus lipomatosus superficialis

  • Abbreviated NLS.
  • AKA nevus lipomatosus cutaneous superficialis, abbreviated NLCS.
  • AKA nevus lipomatosus.[28]

Bullous disease

Cysts

See also

References

  1. Busam, Klaus J. (2009). Dermatopathology: A Volume in the Foundations in Diagnostic Pathology Series (1st ed.). Saunders. pp. 26. ISBN 978-0443066542.
  2. URL: http://www.pediatrics.wisc.edu/education/derm/text.html. Accessed on: 23 August 2012.
  3. URL: http://missinglink.ucsf.edu/lm/DermatologyGlossary/tinea.html. Accessed on: 25 February 2013.
  4. Picascia, DD.; Robinson, JK. (Aug 1987). "Actinic cheilitis: a review of the etiology, differential diagnosis, and treatment.". J Am Acad Dermatol 17 (2 Pt 1): 255-64. PMID 3305604.
  5. Kumar, Vinay; Abbas, Abul K.; Fausto, Nelson; Aster, Jon (2009). Robbins and Cotran pathologic basis of disease (8th ed.). Elsevier Saunders. pp. 1188. ISBN 978-1416031215.
  6. Busam, Klaus J. (2009). Dermatopathology: A Volume in the Foundations in Diagnostic Pathology Series (1st ed.). Saunders. pp. 76. ISBN 978-0443066542.
  7. 7.0 7.1 Busam, Klaus J. (2009). Dermatopathology: A Volume in the Foundations in Diagnostic Pathology Series (1st ed.). Saunders. pp. 77. ISBN 978-0443066542.
  8. URL: http://www.dermnetnz.org/dermal-infiltrative/solar-elastosis.html. Accessed on: 27 March 2013.
  9. Thomas, NE.; Kricker, A.; From, L.; Busam, K.; Millikan, RC.; Ritchey, ME.; Armstrong, BK.; Lee-Taylor, J. et al. (Nov 2010). "Associations of cumulative sun exposure and phenotypic characteristics with histologic solar elastosis.". Cancer Epidemiol Biomarkers Prev 19 (11): 2932-41. doi:10.1158/1055-9965.EPI-10-0686. PMID 20802019.
  10. 10.0 10.1 Karagas, MR.; Zens, MS.; Nelson, HH.; Mabuchi, K.; Perry, AE.; Stukel, TA.; Mott, LA.; Andrew, AS. et al. (Mar 2007). "Measures of cumulative exposure from a standardized sun exposure history questionnaire: a comparison with histologic assessment of solar skin damage.". Am J Epidemiol 165 (6): 719-26. doi:10.1093/aje/kwk055. PMID 17204514.
  11. 11.0 11.1 Humphrey, Peter A; Dehner, Louis P; Pfeifer, John D (2008). The Washington Manual of Surgical Pathology (1st ed.). Lippincott Williams & Wilkins. pp. 480. ISBN 978-0781765275.
  12. URL: http://www.webmd.com/skin-problems-and-treatments/tc/folliculitis-topic-overview. Accessed on: 7 November 2012.
  13. URL: http://www.head-face-med.com/content/4/1/2. Accessed on: 16 January 2014.
  14. Humphrey, Peter A; Dehner, Louis P; Pfeifer, John D (2008). The Washington Manual of Surgical Pathology (1st ed.). Lippincott Williams & Wilkins. pp. 486. ISBN 978-0781765275.
  15. 15.0 15.1 Busam, Klaus J. (2009). Dermatopathology: A Volume in the Foundations in Diagnostic Pathology Series (1st ed.). Saunders. pp. 505. ISBN 978-0443066542.
  16. 16.0 16.1 16.2 Jacyk, WK.; Rütten, A.; Requena, L. (2008). "Fibrous papule of the face with granular cells.". Dermatology 216 (1): 56-9. doi:10.1159/000109359. PMID 18032900.
  17. Humphrey, Peter A; Dehner, Louis P; Pfeifer, John D (2008). The Washington Manual of Surgical Pathology (1st ed.). Lippincott Williams & Wilkins. pp. 492. ISBN 978-0781765275.
  18. 18.0 18.1 Ragaz, A.; Berezowsky, V. (1979). "Fibrous papule of the face. A study of five cases by electron microscopy.". Am J Dermatopathol 1 (4): 353-6. PMID 543528.
  19. 19.0 19.1 Alsaad, KO.; Ghazarian, D. (Dec 2005). "My approach to superficial inflammatory dermatoses.". J Clin Pathol 58 (12): 1233-41. doi:10.1136/jcp.2005.027151. PMID 16311340.
  20. 20.0 20.1 Cotran, Ramzi S.; Kumar, Vinay; Fausto, Nelson; Nelso Fausto; Robbins, Stanley L.; Abbas, Abul K. (2005). Robbins and Cotran pathologic basis of disease (7th ed.). St. Louis, Mo: Elsevier Saunders. pp. 1269. ISBN 0-7216-0187-1.
  21. Kumar, Vinay; Abbas, Abul K.; Fausto, Nelson; Aster, Jon (2009). Robbins and Cotran pathologic basis of disease (8th ed.). Elsevier Saunders. pp. 1185. ISBN 978-1416031215.
  22. Katenkamp D, Kosmehl H, Langbein L (1988). "[Angiomyoma. A pathologo-anatomic analysis of 229 cases]" (in German). Zentralbl Allg Pathol 134 (4-5): 423–33. PMID 3201831.
  23. Shih, CC.; Yu, HS.; Tung, YC.; Tsai, KB.; Cheng, ST. (Jan 2001). "Inverted follicular keratosis.". Kaohsiung J Med Sci 17 (1): 50-4. PMID 11411260.
  24. 24.0 24.1 24.2 Busam, Klaus J. (2009). Dermatopathology: A Volume in the Foundations in Diagnostic Pathology Series (1st ed.). Saunders. pp. 387. ISBN 978-0443066542.
  25. Busam, Klaus J. (2009). Dermatopathology: A Volume in the Foundations in Diagnostic Pathology Series (1st ed.). Saunders. pp. 341. ISBN 978-0443066542.
  26. URL: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC475744/. Accessed on: 11 May 2010.
  27. Gandhi, V.; Dogra, D.; Pandhi, RK.. "Cutaneous focal mucinosis.". Indian J Dermatol Venereol Leprol 62 (4): 260-1. PMID 20948074.
  28. Kaw, P.; Carlson, A.; Meyer, DR. (Jan 2005). "Nevus lipomatosus (pedunculated lipofibroma) of the eyelid.". Ophthal Plast Reconstr Surg 21 (1): 74-6. PMID 15677959.