Difference between revisions of "Non-malignant skin disease"

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'''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.
===General===
*Nodular & diffuse.
*Can be thought of as a localized/focal version of [[lichen simplex chronicus]] (LSC).
*Spongiotic.
*Vasculitis.
*Perivascular.
*Panniculitis.
*Psoriasiform.


'''Tabular comparison of inflammatory skin disease (adapted from ''Brister''<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>):'''
===Gross===
{| class="wikitable"
*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>
| '''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]]<br>-[[Lichen simplex chronicus]] (LSC)
|-
| 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 SC tissue || -Septal<br>-Nodular || -[[Erythema nodosum]]<br>-[[Erythema induratum]]
|-
| Psoriasiform || Epidermal thickening<br>and long rete ridges || -Regular<br>-Irregular || -Psoriasis<br>-?
|}
Notes:
*''DE junction'' = dermal-epidermal junction.
*The "empty space" in bullous disease ''in situ'' is filled with fluid.


===Psoriasis===
===Microscopic===
====General====
*See ''[[lichen simplex chronicus]]''.
*Can be subclassified.


DDx:
DDx:
*Psoriasis vulgaris (most common).
*[[Lichen simplex chronicus]] - a more diffuse process, not a raised lesion.
*Psoriatic arthritis.
*Drug-induced.
*Others.


====Microscopic====
===Sign out===
Features:<ref>{{Ref PBoD8|1191}}</ref>
<pre>
*Epidermal thickened - as very long rete ridges (described as "test tube-morphology") - '''key feature'''.
SKIN LESION, LEFT CHIN, BIOPSY:
**Epidermis between rete ridges thin.
- PRURIGO NODULARIS.
</pre>


==Seborrheic dermatitis==
====Micro====
===General===
The sections show a raised lesion with compact hyperkeratosis and irregular acanthosis.  Spongiosis is seen focally.  There is minimal hypergranulosis.
*Very common.


===Microscopic===
There is no thinning of the suprapapillary plate and no dilated superficial blood vessels. There is no interface activity.
Features:<ref>{{Ref PBoD8|1191}}</ref>
*Spongiosis (epidermal edema).
*Acanthosis (epidermal thickening).
*"Follicular lipping" = parakeratosis with neutrophils.
*Perivascular neutrophils and lymphocytes.


==Systemic lupus erythematosus==
=Very common=
==Dermatomycosis==
:''Dermatophytosis'' redirects here.
===General===
===General===
*Systemic disease with multi-organ manifestations.  
*[[microorganisms|Fungal infection]] of skin.
 
Note:
*''Dermatophytosis'' (ring worm) is a type of dermatomycosis.


===Microscopic===
===Microscopic===
Features:
Features:
*Lymphocytic interface dermatitis.<ref>JAH. 20 February 2009.</ref>
*Microorganisms - '''key feature'''.
*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>
**Often hyphae (candida) - like twigs of a tree... branching.
*Intradermal mucin.
***May be very fragmented in section ~ size of a neutrophil.
*Perivascular inflammation, esp. neutrophils.
*[[Exocytosis]] - blood cell infiltrate the epidermis.
 
====Images====
<gallery>
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>
 
===Stains===
*[[GMS stain]].
*[[PAS-D stain]].
 
===Sign out===
<pre>
SKIN, BIOPSY:
- SKIN WITH SUPERFICIAL FUNGAL ORGANISMS CONSISTENT WITH CANDIDA.
- REACTIVE CHANGES OF THE EPITHELIUM.
</pre>


==Dermatomyositis==
====Micro====
:See: ''[[Neuromuscular_pathology#Dermatomyositis]]''.
The sections show skin with a neutrophilic infiltrate in the superficial epidermis.  PAS-D staining demonstrates fungal organisms with a morphology suggestive of candida.
===Gross===
*Have lesions on the knuckle - Gottron's papulle


===Microsopic===
The epithelium has parakeratosis, acanthosis and spongiosis. No mitotic activity is appreciated.  The keratinocytes are moderately enlarged and have evident nucleoli.
Features:
*Lymphocytic interface dermatitis (inflammation at the dermal-epidermal junction).
*Loss of rete ridges.


==Lichen planus==
==Cicatrix==
===General===
{{Main|Dermal scar}}
*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:
==Fibroepithelial polyp==
*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>
{{Main|Fibroepithelial polyp}}


Clinical:<ref name=Ref_PBoD8_1191>{{Ref PBoD8|1191}}</ref>
==Actinic keratosis==
*6 Ps: pruritic (itchy), purple, polygonal, planar papules and plaques.
{{Main|Actinic keratosis}}


===Gross===
==Actinic cheilitis==
*Wickham striae = white lines/dots.
===General===
**Due to hypergranulosis.
*[[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:<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 ''[[actinic keratosis]]''.
*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:
===Sign out===
*[[Bullous disease]], subepithelial vesicular.
<pre>
LESION, LOWER LIP, BIOPSY:  
- ACTINIC CHEILITIS.
- SOLAR ELASTOSIS.
</pre>


Notes:
====Micro====
*Hyperkeratosis and hypergranulosis are not seen in [[erythema multiforme]].
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.
*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>
**DDx: systemic lupus erythematosus, lichen planus, and [[graft-versus-host disease]].


Images:
==Seborrheic keratosis==
*[http://commons.wikimedia.org/wiki/File:Lichen_planus_intermed_mag.jpg Lichen planus - intermed. mag. (WC)]
{{Main|Seborrheic keratosis}}
*[http://commons.wikimedia.org/wiki/File:Lichen_planus_low_mag.jpg Lichen planus - low mag. (WC)].


==Lichen sclerosus==  
==Pilomatricoma==
{{Main|Lichen sclerosus}}
{{Main|Pilomatricoma}}


===Microscopic===
==Dermatofibroma==
Features:<ref name=Ref_PBoD1065-6>{{Ref PBoD|1065-6}}</ref>
{{Main|Dermatofibroma}}
*Subepithelial fibrosis - '''key feature'''.


==Psoriasis==
==Ezcema==
===General===
===General===
*Chronic skin condition +/- systemic involvement:<ref name=Ref_PCPBoD8_603>{{Ref PCPBoD8|603}}</ref>
*A nebulous thingy.
**[[Arthritis]].
*Very common.
**[[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:
DDx:
*''Auspitz sign'' = pin-point bleeding on removal of scale.
*Contact allergy.
*''Koebner phenomenon'' = lesions form at site of trauma.
*[[Drug reaction]].
*Food allergy.


===Microscopic===
===Microscopic===
Features:<ref name=Ref_PCPBoD8_603>{{Ref PCPBoD8|603}}</ref>
Features:<ref>{{Ref PBoD8|1188}}</ref>
*Acanthosis + long rete ridges - '''key feature'''.
*Spongiosis (epidermal edema); keratinocytes spacing increased - '''key feature'''.
*Parakeratosis.
*+/-Interdermal vesicles.
*Dilated vessels in superficial dermis (give rise to ''Auspitz sign'').
*+/-Eosinophils (may suggest Rx reaction).
*Spongiform pustules = PMNs in stratum spinosum.
*Perivascular lymphocytes.
*PMNs in parakeratotic stratum corneum (Munro microabscess).
 
=Other=
==Squamous cell hyperplasia==
*[[AKA]] ''lichen simplex chronicus''.<ref name=Ref_PBoD1011>{{Ref PBoD8|1011}}</ref>


==Acne vulgaris==
===General===
===General===
*Variant of ''spongiotic dermatitis''.<ref name=Ref_DCHH296>{{Ref DCHH|296}}</ref>
*Extremely common - esp. among adolescents.
*Very rarely seen by pathologists.


Etiology:<ref>URL: [http://emedicine.medscape.com/article/1123423-overview http://emedicine.medscape.com/article/1123423-overview]. Accessed on: 20 August 2010.</ref>
Treatments:
*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>.
*Antibiotic (minocycline).
*Isotretinoin [[AKA]] all-trans retinoic acid (ATRA).


===Microscopic===
===Gross===
Features:<ref name=Ref_PBoD1065-6>{{Ref PBoD|1065-6}}</ref>
*Papules, pustules, nodules or cysts.
*Acanthosis (epithelial thickening).  
**White, black or erythematous.
*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:
Images:
*[http://commons.wikimedia.org/w/index.php?title=File:Lichen_simplex_chronicus_-_low_mag.jpg LSC - low mag. (WC)].
*[http://commons.wikimedia.org/wiki/File:Blackheads.JPG Blackheads (WC)].
*[http://commons.wikimedia.org/w/index.php?title=File:Lichen_simplex_chronicus_-_high_mag.jpg LSC - high mag. (WC)].
 
=Very common=
==Dermatophytosis==
===General===
*[[microorganisms|Fungal infection]] of skin.


===Microscopic===
===Microscopic===
Features:
Features:<ref>{{Ref Derm|76}}</ref>
*Microorganisms - '''key feature'''.
*Folliculitis:<ref name=Ref_Derm77>{{Ref Derm|77}}</ref>
**Often hyphae (candida) - like twigs of a tree... branching.
**[[Neutrophil]]s around hair follicle and infiltrate into it - including the follicular canal.
*Perivascular inflammation.
*Epidermal invagination ''or'' cyst at site of a hair follicle - contains:
*Exocytosis - blood cell infiltrate the epidermis.
**Sebum.
**+/-Bacteria (''Propionibacterium acnes'') and inflammatory cells - typically neurophils.


===Stains===
Subtyped into:
*[[GMS]].
#Open comedones ("blackheads") - no extension to epidermal surface.
*[[PAS]].
#Closed comedones ("whiteheads") - to epidermal surface have wide opening.


==Cicatrix==
DDx - acneiform disorder:<ref name=Ref_Derm77>{{Ref Derm|77}}</ref>
*[[AKA]] ''scar''.
*[[Rosacea]].
===General===
*Infective folliculitis.
*Previous surgery, biopsy, trauma.
*Perioral dermatitis.
 
*Acne vulgaris.
===Microscopic===
Features:
*Loss of adnexal structures.
*Dense collagen - fibers run parallel to the dermal-epidermal (DE) junction.
*Loss of dermal papilla.


Image:
Image:
*[http://commons.wikimedia.org/wiki/File:ScarHistology.JPG Scar (WC)].
*[http://www.dermnet.com/images/Acne-Histology/picture/4069 Acne (dermnet.com)].


==Fibroepithelial polyp==
==Solar elastosis==
*[[AKA]] ''acrochordon'', ''skin tag''.
*[[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===
===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.
*Benign.
*Older people.
*May be associated with pregnancy, diabetes, intestinal polyposis.<ref name=Ref_PCPBoD8|596>{{Ref PCPBoD8|596}}</ref>
===Gross===
*Raised skin-coloured lesion.
Image:
*[http://commons.wikimedia.org/wiki/File:Skintagblemish.jpg Skin tag (WC)].


===Microscopic===
===Microscopic===
Features:
Features:
*On a stalk / epithelium on three sides.
*Grey, spaghetti-like material in the superficial dermis.
*Benign epidermis.


Image:
DDx:
*[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]].
*[[Basal cell carcinoma]].
*[[Squamous cell carcinoma of the skin|Squamous cell carcinoma]].


==Actinic keratosis==
Note:
*AKA solar keratosis. (???)
*The DDx above is things associated with sun damaged skin.
===General===
*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.
Clinical: yellow-brown scaly, patches, sandpaper sensation.


Risk factors:<ref name=Ref_PBoD8_1180>{{Ref PBoD8|1180}}</ref>  
====Images====
*Sun exposure.
<gallery>
*Immune suppression (e.g. organ transplant recipients).
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)].


===Microscopic===
===Sign out===
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>
<pre>
*Epidermal nuclear atypia:
SKIN, RIGHT CHEEK, RE-EXCISION:
**Variation is size, shape and staining.
- DERMAL SCAR.
***Nuclear enlargement - '''key feature'''.
- EXTENSIVE SOLAR ELASTOSIS.
****Should involve the basal layer.
</pre>
*Abnormal epidermal architecture:
**Pallisading. (???)
*+/-Parakeratosis.
*+/-Irregular acanthosis.


Image:
=====Prominent blood vessels=====
*[http://commons.wikimedia.org/wiki/File:Actinic_Keratosis,_H%26E.jpg Actinic keratosis (WC)].
<pre>
SKIN LESION, LEFT CHEEK, BIOPSY:
- SKIN WITH SOLAR ELASTOSIS AND PROMINENT SMALL BLOOD VESSELS.
</pre>


==Seborrheic keratosis==
<pre>
*Abbreviated ''SK''.
SUPERIOR SHOULDER, LEFT, PUNCH BIOPSY:
===General===
- BENIGN SKIN WITH MODERATE SOLAR ELASTOSIS, PROMINENT SMALL BLOOD VESSELS AND
*Benign.
  SCATTERED PERIVASCULAR LYMPHOCYTES AND PLASMA CELLS.
*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>
- NEGATIVE FOR BASAL CELL CARCINOMA.
*"Large number" of SKs = paraneoplastic syndrome (''Leser–Trélat sign'').<ref name=Ref_PCPBoD8_595>{{Ref PCPBoD8|595}}</ref>
- NEGATIVE FOR ACTINIC KERATOSIS.
</pre>


Epidemiology:
====Micro====
*Old people.
The sections show hair bearing skin with solar elastosis and numerous small dilated blood vessels. The dermis is mildly fibrotic. Compact keratin is present.
*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>


===Gross===
The epidermis matures to the surface. A granular layer is present. There is no basal
*"Stuck-on" appearance - raised lesion.
epidermal atypia. No melanocytic nests are identified. There is no palisading of the basal
cells. Rare scattered lymphocytes are in the dermis.


Image(s):
=Very common - viral=
*[http://www.dermatlas.org/derm/IndexDisplay.cfm?ImageID=91774460 SK - gross image (dermatlas.org)].
==Verruca vulgaris==
{{Main|Verruca vulgaris}}


===Microscopic===
==Verruca plana==
Features:<ref name=Ref_PCPBoD8_595>{{Ref PCPBoD8|595}}</ref>
*Raised above skin surface.
*Border sharply demarcated.
*Hyperkeratosis - stratum corneum extra thick.
*Horn cysts - intraepidermal collections of keratin.
*Clusters of cells with brown granular material in the superficial dermis/dermoepidermal junction - pigmented melanocytes.
 
Images:
*[http://commons.wikimedia.org/wiki/File:Seborrheic_keratosis_(1).jpg Seborrheic keratosis - low mag. (WC)].
*[http://commons.wikimedia.org/wiki/File:Seborrheic_keratosis_%282%29.jpg Seborrheic keratosis - high mag. (WC)].
*[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)].
 
==Verruca vulgaris==
===General===
===General===
*[[AKA]] common wart.
*Common.
*Etiology - [[HPV]].
*Usu. hands and face.<ref name=Ref_WMSP480>{{Ref WMSP|480}}</ref>
 
Notes:
*Related to [[condyloma acuminatum]].


===Microscopic===
===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>
Features:<ref name=Ref_WMSP480>{{Ref WMSP|480}}</ref>
*Hyperkeratosis (more keratin - thick stratum corneum).
*Orthokeratosis with basketweave pattern.
*Hypergranulosis (thicker stratum granulosum).
*Hypergranulosis.
*Acanthosis (thickening of the stratum spinosum).
*Viral keratohyaline.
*Rete ridges lengthened (~7-10x normal).
*Koilocytes.
*Large blood vessels at the dermal-epidermal junction.
*[[Acanthosis]] - yet flat surface and base.


Memory device: there is more of everything - more s. corneum, s. granulosum, s. spinosum, longer rete ridges, more (larger) blood vessels.
Notes:
*It differs from [[verruca vulgaris]]... (1) orthokeratosis, (2) flat surface and base.


Images:
=Less common=
*[http://commons.wikimedia.org/wiki/File:Verruca_vulgaris_-_very_low_mag.jpg Verruca vulgaris - very low mag. (WC)].
==Chronic folliculitis==
*[http://commons.wikimedia.org/wiki/File:Verruca_vulgaris_-_intermed_mag.jpg Verruca vulgaris - intermed mag. (WC)].
:''Folliculitis'' redirect here.
 
==Pilomatricoma==
*[[AKA]] ''calcifying epithelioma of Malherbe''<ref>{{Ref Derm|387}}</ref>, [[AKA]] ''pilomatrixoma''.
===General===
===General===
*Benign skin tumour.
*Common.
*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>
*Infrequently biopsied.
*CTNNB1 gene mutation important in pathogenesis.<ref name=Ref_PCPBoD8_597>{{Ref PCPBoD8|597}}</ref>


Clinical:
===Gross===
*Hard nodule - calcification.
*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>
*+/-Painful.


Treatment:
DDx gross:
*Surgical excision.<ref name=emed1058965>[http://emedicine.medscape.com/article/1058965-overview http://emedicine.medscape.com/article/1058965-overview]</ref>
*[[Melanocytic lesion]]s.


===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.
*Inflammation around the hair follicle - '''key feature'''.
**Sharpy demarcated island of cells.
**Lymphocytes - usu. predominant.
**Calcification in 75% - with calcium staining (von Kossa).  
*+/-Chronic changes:
*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>
**[[Acanthosis]].
**Basaloid epithelial cells - have prominent nucleoli.
**Hyperkeratosis.
**Anucleate squamous cells ("ghost cells").  
**Hypergranulosis.
**Giant cell foreign body type [[granulomas]] (form in reaction to keratin).


Notes:
DDx:
*Keratin a prominent feature on cytology - lots of orange stuff.
*[[Acne vulgaris]].


Images:
===Sign out===
*[http://www.bccancer.bc.ca/HPI/CE/cytotechnology/cytosleuthquiz/nongyne/ngcase02.htm Pilomatrixoma - cytology (bccancer.bc.ca)].
<pre>
*[http://www.dermrounds.com/photo/1980062:Photo:431 Pilomatrixoma - histology (dermrounds.com)].
SKIN LESION, UPPER ARM, BIOPSY:
*[http://en.wikipedia.org/wiki/File:Pilomatrixoma_-_high_mag.jpg Pilomatrixoma - high mag. (WC)].
- CHRONIC FOLLICULITIS WITH SECONDARY SURFACE CHANGES.
*[http://en.wikipedia.org/wiki/File:Pilomatrixoma_-_intermed_mag.jpg Pilomatrixoma - intermed. mag. (WC)].
</pre>


DDx:
====Micro====
*[[Epidermal inclusion cyst]].
The sections show hair-bearing skin with abundant lymphocytes around and within the hair follicle wall.  


==Dermatofibroma==
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.
*Abbreviated ''DF''.
===General===
*AKA ''fibrous histiocytoma''.
*Reactive process -- it is ''not'' a neoplasm.
*Usually associated with previous trauma.
**In women... usually legs.


===Microscopic===
There are no granulomas.
Features:<ref name=Ref_WMSP492>{{Ref WMSP|492}}</ref>
*Prominent fibrous bundles, especially at the edge of the lesion.
**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:
==Clear cell acanthoma==
*[http://missinglink.ucsf.edu/lm/DermatologyGlossary/dermatofibroma.html Dermatofibroma (ucsf.edu)].
{{Main|Clear cell acanthoma}}
*[http://www.pacificderm.org/newsflashcpcapril04.html DF - several images (pacificderm.org)].


DDx:
==Chondrodermatitis nodularis chronica helicis==
*[[Dermatofibrosarcoma protuberans]] (DFSP).
*[[AKA]] ''chondrodermatitis nodularis helicis''.
*[[Neurofibroma]].
*Abbreviated ''CNCH''.
*[[Blue nevus]].
*[[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>
*[[Melanoma]].
{{Main|Chondrodermatitis nodularis chronica helicis}}


====Subtypes====
==Cutaneous calcinosis==
Like all common things... there are subtypes:<ref>{{Ref Sternberg5|51}}</ref>
*[[AKA]] ''calcinosis cutis''.
*Cellular.
{{Main|Cutaneous calcinosis}}
*Deep penetrating.
*Lipidized - with foamy macrophages, hemorrhage and Touton-like giant cells.
*Epithelioid cell histiocytoma.
*Fibrotic.
*Aneurysmal - large blood filled + features of ''lipidized''.
*Granular cell dermatofibroma.
*Dermatofibroma with monster cells.


===IHC===
==Dilated pore of Winer==
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>
*Factor XIIIa +ve.
**Usually negative in [[DFSP]].
*CD34 -ve.
**Usually positive in DFSP.
*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>
**Usually negative in DFSP.
 
==Ezcema==
===General===
===General===
*A nebulous thingy.
*Benign.
*Very common.
*Looks like a zit.
 
DDx:
*Contact allergy.
*Drug reaction.
*Food allergy.


===Microscopic===
===Microscopic===
Features:<ref>{{Ref PBoD8|1188}}</ref>
Features:<ref name=Ref_WMSP486>{{Ref WMSP|486}}</ref>
*Spongiosis (epidermal edema); keratinocytes spacing increased - '''key feature'''.
*Dilated hair follicle with keratin.
*+/-Interdermal vesicles.
*[[Acanthosis]].
*+/-Eosinophils (may suggest Rx reaction).
*Budding of epidermis (into dermis).
*Perivascular lymphocytes.


=Less common=
DDx:
==Granuloma annulare==
*[[Pilar sheath acanthoma]].
===General===
*Benign and self-limited condition.
*Etiology unknown - may be assoc. with trauma.<ref name=Ref_Derm51>{{Ref Derm|51}}</ref>


===Microscopic===
Image:
Features:<ref name=Ref_WMSP478>{{Ref WMSP|478}}</ref>
*[http://dermpathexpert.com/id90.html Dilated pore of Winer (dermpathexpert.com)].
*Dermal palisading [[granuloma]] around:
**Necrotic collagen - '''key feature'''.
***Nuclei "missing" - have undergone karyolysis.
**Mucin.
***Loose/pale, paucicellular, eosinophilic.
*Chronic inflammatory cells.


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


DDx:
==Granuloma annulare==
*Necrobiosis lipoidica - little mucin, no normal dermis between foci.<ref name=Ref_Derm51>{{Ref Derm|51}}</ref>
{{Main|Granuloma annulare}}
*[[Rheumatoid nodule]].


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


==Keloid==
==Keloid==
===General===
{{Main|Keloid}}
*Sites of previous trauma/surgery, esp. in dark skinned individuals.<ref name=Ref_WMSP492>{{Ref WMSP|492}}</ref>


===Microscopic===
==Angiofibroma==
Features:<ref name=Ref_WMSP492>{{Ref WMSP|492}}</ref>
:See also: ''[[nasopharyngeal angiofibroma]]''.
*Thick collagen bundles - surrounded by paler staining fibroblasts - '''key feature'''.
:Should '''not''' be confused with ''[[angiokeratoma]]''.
*Lesion replaces adnexal structures, e.g. hair, sweat glands.
{{Main|Angiofibroma}}


Images:
==Benign fibrous papule==
*[http://missinglink.ucsf.edu/lm/DermatologyGlossary/keloids.html Keloids (ucsf.edu)].
*[[AKA]] ''fibrous papule''.


==Angiofibroma==
:See also: ''[[nasopharyngeal angiofibroma]]''.
===General===
===General===
*May be seen in the context of [[tuberous sclerosis]] - esp. "butterfly area of the face".<ref name=Ref_WMSP492>{{Ref WMSP|492}}</ref>
*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>


Clinical:
===Gross===
*Firm, dome-shaped, flesh coloured.
*Solitary lesion of the face - '''important'''.<ref name=Ref_Derm505>{{Ref Derm|505}}</ref>
**Usually on the nose.<ref name=pmid18032900/>


===Microscopic===
===Microscopic===
Line 451: Line 345:
**Enlarged fibroblasts.
**Enlarged fibroblasts.
*Dilated small vessels.
*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/>


Image:
DDx:
*[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>
*[[Angiofibroma]] - not solitary or not on the nose.


==Molluscum contagiosum==
Note:
===General===
*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>
*Etiology: caused by ''molluscum contagiosum virus''.


===Microscopic===
===Images===
Features:
*[http://www.dermaamin.com/site/histopathology-of-the-skin/58-f/1739-fibrous-papule-angiofibroma-.html Fibrous papule (dermaamin.com)].
*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):
===Sign out===
*[http://commons.wikimedia.org/wiki/File:Molluscum_contagiosum_high_mag.jpg Molluscum contagiosum - high mag. (WC)].
<pre>
*[http://commons.wikimedia.org/wiki/File:Molluscum_contagiosum_low_mag.jpg Molluscum contagiosum - low magnification (WC)].
SKIN LESION, CHIN, BIOPSY:
- BENIGN FIBROUS PAPULE.
</pre>


Notes:
==Molluscum contagiosum==
*Molluscum bodies very vaguely resemble ''[[signet ring cell]]s'' -- but:
{{Main|Molluscum contagiosum}}
**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==
===General===
*Benign sweat duct tumour.
*Eccrine differentiation.
*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==
*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>
 
===General===
*Mixed apocrine & eccrine tumour of skin, usu. in the head & neck<ref name=pmid19693940/>, esp. nose and cheek.<ref name=pmid19633639/>
*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===
Features:
*Mix tumour with:<ref name=pmid19693940/>
*#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===
Features:
*Nests of cells that are surrounded by hyaline (i.e. glassy, eosinophilic, acellular) material.
 
Images:
*[http://commons.wikimedia.org/wiki/File:Dermal_cylindroma_intermed_mag.jpg Dermal cylindroma (WC)].
*[http://commons.wikimedia.org/wiki/File:Dermal_cylindroma_intermed_mag_deep.jpg Dermal cylindroma - high mag. (WC)].
 
==Keratoacanthoma==
*Abbreviated ''KA''.
*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===
*May grow rapidly (weeks or months) then involute.
*Main DDx is [[squamous cell carcinoma]].
*Exophytic lesion, well-circumscribed.
 
===Microscopic===
Features:<ref>{{Ref Klatt|378}}</ref>
*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 570: 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 611: 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 619: 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 656: 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 699: 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==
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=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.