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 || -?<br>-[[Erythema nodosum]]
|-
| 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====
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===
===General===
*Very common.
*[[microorganisms|Fungal infection]] of skin.
 
Note:
*''Dermatophytosis'' (ring worm) is a type of dermatomycosis.


===Microscopic===
===Microscopic===
Features:<ref>{{Ref PBoD8|1191}}</ref>
Features:
*Spongiosis (epidermal edema).
*Microorganisms - '''key feature'''.
*Acanthosis (epidermal thickening).
**Often hyphae (candida) - like twigs of a tree... branching.
*"Follicular lipping" = parakeratosis with neutrophils.
***May be very fragmented in section ~ size of a neutrophil.
*Perivascular neutrophils and lymphocytes.
*Perivascular inflammation, esp. neutrophils.
*[[Exocytosis]] - blood cell infiltrate the epidermis.


==Lichen planus==
====Images====
===General===
<gallery>
*An oral pathology.
Image:Dermatomycosis_-_intermed_mag.jpg | Dermatomycosis - intermed. mag. (WC)
*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>
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>


Etiology:
===Stains===
*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>
*[[GMS stain]].
*[[PAS-D stain]].


Clinical:<ref name=Ref_PBoD8_1191>{{Ref PBoD8|1191}}</ref>
===Sign out===
*6 Ps: pruritic (itchy), purple, polygonal, planar papules and plaques.
<pre>
SKIN, BIOPSY:
- SKIN WITH SUPERFICIAL FUNGAL ORGANISMS CONSISTENT WITH CANDIDA.
- REACTIVE CHANGES OF THE EPITHELIUM.
</pre>


===Gross===
====Micro====
*Wickham striae = white lines/dots.
The sections show skin with a neutrophilic infiltrate in the superficial epidermis. PAS-D staining demonstrates fungal organisms with a morphology suggestive of candida.
**Due to hypergranulosis.


===Microscopic===
The epithelium has parakeratosis, acanthosis and spongiosis. No mitotic activity is appreciated. The keratinocytes are moderately enlarged and have evident nucleoli.
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>
*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:
==Cicatrix==
*[[Bullous disease]], subepithelial vesicular.
{{Main|Dermal scar}}


Notes:
==Fibroepithelial polyp==
*Hyperkeratosis and hypergranulosis are not seen in [[erythema multiforme]].
{{Main|Fibroepithelial polyp}}
*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:
==Actinic keratosis==
*[http://commons.wikimedia.org/wiki/File:Lichen_planus_intermed_mag.jpg Lichen planus - intermed. mag. (WC)]
{{Main|Actinic keratosis}}
*[http://commons.wikimedia.org/wiki/File:Lichen_planus_low_mag.jpg Lichen planus - low mag. (WC)].


==Lichen sclerosus==  
==Actinic cheilitis==
{{Main|Lichen sclerosus}}
===General===
*[[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 name=Ref_PBoD1065-6>{{Ref PBoD|1065-6}}</ref>
:See ''[[actinic keratosis]]''.
*Subepithelial fibrosis - '''key feature'''.


==Psoriasis==
===Sign out===
===General===
<pre>
*Chronic skin condition +/- systemic involvement:<ref name=Ref_PCPBoD8_603>{{Ref PCPBoD8|603}}</ref>
LESION, LOWER LIP, BIOPSY:
**[[Arthritis]].
- ACTINIC CHEILITIS.
**[[Myopathy]].
- SOLAR ELASTOSIS.
**Enteropathy, e.g. [[inflammatory bowel disease]].
</pre>
**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:
====Micro====
*''Auspitz sign'' = pin-point bleeding on removal of scale.
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.
*''Koebner phenomenon'' = lesions form at site of trauma.


===Microscopic===
==Seborrheic keratosis==
Features:<ref name=Ref_PCPBoD8_603>{{Ref PCPBoD8|603}}</ref>
{{Main|Seborrheic keratosis}}
*Acanthosis + long rete ridges - '''key feature'''.
 
*Parakeratosis.
==Pilomatricoma==
*Dilated vessels in superficial dermis (give rise to ''Auspitz sign'').
{{Main|Pilomatricoma}}
*Spongiform pustules = PMNs in stratum spinosum.
*PMNs in parakeratotic stratum corneum (Munro microabscess).


=Other=
==Dermatofibroma==
==Squamous cell hyperplasia==
{{Main|Dermatofibroma}}
*[[AKA]] ''lichen simplex chronicus''.<ref name=Ref_PBoD1011>{{Ref PBoD8|1011}}</ref>


==Ezcema==
===General===
===General===
*Variant of ''spongiotic dermatitis''.<ref name=Ref_DCHH296>{{Ref DCHH|296}}</ref>
*A nebulous thingy.
*Very common.


Etiology:<ref>URL: [http://emedicine.medscape.com/article/1123423-overview http://emedicine.medscape.com/article/1123423-overview]. Accessed on: 20 August 2010.</ref>
DDx:
*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>.
*Contact allergy.
*[[Drug reaction]].
*Food allergy.


===Microscopic===
===Microscopic===
Features:<ref name=Ref_PBoD1065-6>{{Ref PBoD|1065-6}}</ref>
Features:<ref>{{Ref PBoD8|1188}}</ref>
*Acanthosis (epithelial thickening).  
*Spongiosis (epidermal edema); keratinocytes spacing increased - '''key feature'''.
*Hyperkeratosis.
*+/-Interdermal vesicles.
Other features:<ref>URL: [http://emedicine.medscape.com/article/1123423-diagnosis http://emedicine.medscape.com/article/1123423-diagnosis]. Accessed on: 20 August 2010.</ref>
*+/-Eosinophils (may suggest Rx reaction).
*Spongiosis (epidermal intercellular edema -- cells appear to have a clear halo around 'em).
*Perivascular lymphocytes.
*Parakeratosis = retention of nuclei in the stratum corneum.


Images:
==Acne vulgaris==
*[http://commons.wikimedia.org/w/index.php?title=File:Lichen_simplex_chronicus_-_low_mag.jpg LSC - low mag. (WC)].
===General===
*[http://commons.wikimedia.org/w/index.php?title=File:Lichen_simplex_chronicus_-_high_mag.jpg LSC - high mag. (WC)].
*Extremely common - esp. among adolescents.
*Very rarely seen by pathologists.


=Very common=
Treatments:
==Fibroepithelial polyp==
*Antibiotic (minocycline).
*[[AKA]] ''acrochordon'', ''skin tag''.
*Isotretinoin [[AKA]] all-trans retinoic acid (ATRA).
===General===
*Benign.
*Older people.
*May be associated with pregnancy, diabetes, intestinal polyposis.<ref name=Ref_PCPBoD8|596>{{Ref PCPBoD8|596}}</ref>


===Gross===
===Gross===
*Raised skin-coloured lesion.
*Papules, pustules, nodules or cysts.
**White, black or erythematous.


Image:
Images:
*[http://commons.wikimedia.org/wiki/File:Skintagblemish.jpg Skin tag (WC)].
*[http://commons.wikimedia.org/wiki/File:Blackheads.JPG Blackheads (WC)].


===Microscopic===
===Microscopic===
Features:
Features:<ref>{{Ref Derm|76}}</ref>
*On a stalk / epithelium on three sides.
*Folliculitis:<ref name=Ref_Derm77>{{Ref Derm|77}}</ref>
*Benign epidermis.
**[[Neutrophil]]s 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:
#Open comedones ("blackheads") - no extension to epidermal surface.
#Closed comedones ("whiteheads") - to epidermal surface have wide opening.
 
DDx - acneiform disorder:<ref name=Ref_Derm77>{{Ref Derm|77}}</ref>
*[[Rosacea]].
*Infective folliculitis.
*Perioral dermatitis.
*Acne vulgaris.


Image:
Image:
*[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>
*[http://www.dermnet.com/images/Acne-Histology/picture/4069 Acne (dermnet.com)].


==Seborrheic keratosis==
==Solar elastosis==
*Abbreviated ''SK''.
*[[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.
*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>
*"Large number" of SKs = paraneoplastic syndrome (''Leser–Trélat sign'').<ref name=Ref_PCPBoD8_595>{{Ref PCPBoD8|595}}</ref>


Epidemiology:
===Microscopic===
*Old people.
Features:
*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>
*Grey, spaghetti-like material in the superficial dermis.


===Gross===
DDx:
*"Stuck-on" appearance - raised lesion.
*[[Actinic keratosis]].
*[[Basal cell carcinoma]].
*[[Squamous cell carcinoma of the skin|Squamous cell carcinoma]].


Image(s):  
Note:
*[http://www.dermatlas.org/derm/IndexDisplay.cfm?ImageID=91774460 SK - gross image (dermatlas.org)].
*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.


===Microscopic===
====Images====
Features:<ref name=Ref_PCPBoD8_595>{{Ref PCPBoD8|595}}</ref>
<gallery>
*Raised above skin surface.  
Image:Solar_elastosis_-_intermed_mag.jpg | Solar elastosis - intermed. mag. (WC)
*Border sharply demarcated.
Image:Solar_elastosis_-_high_mag.jpg | Solar elastosis - high mag. (WC)
*Hyperkeratosis - stratum corneum extra thick.
</gallery>
*Horn cysts - intraepidermal collections of keratin.
www:
*Clusters of cells with brown granular material in the superficial dermis/dermoepidermal junction - pigmented melanocytes.  
*[http://dermpathexpert.com/id88.html Solar elastosis - several images (dermpathexpert.com)].


Images:
===Sign out===
*[http://commons.wikimedia.org/wiki/File:Seborrheic_keratosis_(1).jpg Seborrheic keratosis - low mag. (WC)].
<pre>
*[http://commons.wikimedia.org/wiki/File:Seborrheic_keratosis_%282%29.jpg Seborrheic keratosis - high mag. (WC)].
SKIN, RIGHT CHEEK, RE-EXCISION:
*[http://www.dermatlas.org/derm/IndexDisplay.cfm?ImageID=-1985374774 Seborrheic keratosis - high mag. (dermatlas.org)].
- DERMAL SCAR.
*[http://www.dermatlas.org/derm/IndexDisplay.cfm?ImageID=-1880960893 Seborrheic keratosis - low mag.  (dermatlas.org)].
- EXTENSIVE SOLAR ELASTOSIS.
</pre>


==Verruca vulgaris==
=====Prominent blood vessels=====
===General===
<pre>
*[[AKA]] common wart.
SKIN LESION, LEFT CHEEK, BIOPSY:
*Etiology - [[HPV]].
- SKIN WITH SOLAR ELASTOSIS AND PROMINENT SMALL BLOOD VESSELS.
</pre>


Notes:
<pre>
*Related to [[condyloma acuminatum]].
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.
</pre>


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


Images:
=Very common - viral=
*[http://commons.wikimedia.org/wiki/File:Verruca_vulgaris_-_very_low_mag.jpg Verruca vulgaris - very low mag. (WC)].
==Verruca vulgaris==
*[http://commons.wikimedia.org/wiki/File:Verruca_vulgaris_-_intermed_mag.jpg Verruca vulgaris - intermed mag. (WC)].
{{Main|Verruca vulgaris}}


==Pilomatricoma==
==Verruca plana==
*[[AKA]] pilomatrixoma.
===General===
===General===
*Benign skin tumour.
*Common.
*Most common solid skin tumour of children.<ref name=emed1058965>[http://emedicine.medscape.com/article/1058965-overview http://emedicine.medscape.com/article/1058965-overview]</ref>
*Usu. hands and face.<ref name=Ref_WMSP480>{{Ref WMSP|480}}</ref>
 
Clinical:
*Hard nodule - calcification.
*+/-Painful. (???)
 
Treatment:
*Surgical excision.<ref name=emed1058965>[http://emedicine.medscape.com/article/1058965-overview http://emedicine.medscape.com/article/1058965-overview]</ref>


===Microscopic===
===Microscopic===
Features:<ref name=emed1058965dx>[http://emedicine.medscape.com/article/1058965-diagnosis http://emedicine.medscape.com/article/1058965-diagnosis]</ref>
Features:<ref name=Ref_WMSP480>{{Ref WMSP|480}}</ref>
*Location: lower dermis/subcutaneous fat; thus, usu. surrounded by connective tissue.
*Orthokeratosis with basketweave pattern.
*Sharpy demarcated island of cells.
*Hypergranulosis.
*Calcification in 75% - with calcium staining (von Kossa).  
*Viral keratohyaline.
*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>
*Koilocytes.
**Basaloid epithelial cells - have prominent nucleoli.
*[[Acanthosis]] - yet flat surface and base.
**Anucleate squamous cells ("ghost cells").  
*Giant cell foreign body type [[granulomas]] (form in reaction to keratin).


Notes:
Notes:
*Keratin a prominent feature on cytology - lots of orange stuff.
*It differs from [[verruca vulgaris]]... (1) orthokeratosis, (2) flat surface and base.


Images:
=Less common=
*[http://www.bccancer.bc.ca/HPI/CE/cytotechnology/cytosleuthquiz/nongyne/ngcase02.htm Pilomatrixoma - cytology (bccancer.bc.ca)].
==Chronic folliculitis==
*[http://www.dermrounds.com/photo/1980062:Photo:431 Pilomatrixoma - histology (dermrounds.com)].
:''Folliculitis'' redirect here.
*[http://en.wikipedia.org/wiki/File:Pilomatrixoma_-_high_mag.jpg Pilomatrixoma - high mag. (WC)].
===General===
*[http://en.wikipedia.org/wiki/File:Pilomatrixoma_-_intermed_mag.jpg Pilomatrixoma - intermed. mag. (WC)].
*Common.
*Infrequently biopsied.


DDx:
===Gross===
*[[Epidermal inclusion cyst]].
*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>


==Dermatofibroma==
DDx gross:
*Abbreviated ''DF''.
*[[Melanocytic lesion]]s.
===General===
*AKA ''fibrous histiocytoma''.
*Reactive process -- it is ''not'' a neoplasm.
*Usually associated with previous trauma.
**In women... usually legs.


===Microscopic===
===Microscopic===
Features:<ref name=Ref_WMSP492>{{Ref WMSP|492}}</ref>
Features:
*Prominent fibrous bundles, especially at the edge of the lesion.
*Inflammation around the hair follicle - '''key feature'''.
**Surrounded by spindle cells (fibroblasts).
**Lymphocytes - usu. predominant.
***Usually thought of as fibroblasts surrounded by fibrous material ("collagen-trapping").
*+/-Chronic changes:
*Lack of adnexal structures, i.e. no sweat glands, no hair.
**[[Acanthosis]].
*+/-Epidermal changes - known as "dirty fingers":<ref>BD. 13 April 2011.</ref>
**Hyperkeratosis.
**Acanthosis (thickened epithelial layer - specifically thickened ''stratum spinosum'').
**Hypergranulosis.
**Basal keratinocyte hyperpigmentation.
 
DDx:
*[[Acne vulgaris]].


Images:
===Sign out===
*[http://missinglink.ucsf.edu/lm/DermatologyGlossary/dermatofibroma.html Dermatofibroma (ucsf.edu)].
<pre>
*[http://www.pacificderm.org/newsflashcpcapril04.html DF - several images (pacificderm.org)].
SKIN LESION, UPPER ARM, BIOPSY:
- CHRONIC FOLLICULITIS WITH SECONDARY SURFACE CHANGES.
</pre>


DDx:
====Micro====
*[[Dermatofibrosarcoma protuberans]] (DFSP).
The sections show hair-bearing skin with abundant lymphocytes around and within the hair follicle wall.  
*[[Neurofibroma]].
*[[Blue nevus]].
*[[Melanoma]].


====Subtypes====
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.
Like all common things... there are subtypes:<ref>{{Ref Sternberg5|51}}</ref>
*Cellular.
*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===
There are no granulomas.
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==
==Clear cell acanthoma==
===General===
{{Main|Clear cell acanthoma}}
*A nebulous thingy.
*Very common.


DDx:
==Chondrodermatitis nodularis chronica helicis==
*Contact allergy.
*[[AKA]] ''chondrodermatitis nodularis helicis''.
*Drug reaction.
*Abbreviated ''CNCH''.
*Food allergy.
*[[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}}


===Microscopic===
==Cutaneous calcinosis==
Features:<ref>{{Ref PBoD8|1188}}</ref>
*[[AKA]] ''calcinosis cutis''.
*Spongiosis (epidermal edema); keratinocytes spacing increased - '''key feature'''.
{{Main|Cutaneous calcinosis}}
*+/-Interdermal vesicles.
*+/-Eosinophils (may suggest Rx reaction).
*Perivascular lymphocytes.


=Less common=
==Dilated pore of Winer==
==Molluscum contagiosum==
===General===
*Etiology: caused by ''molluscum contagiosum virus''.
*Benign.
*Looks like a zit.


===Microscopic===
===Microscopic===
Features:
Features:<ref name=Ref_WMSP486>{{Ref WMSP|486}}</ref>
*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>
*Dilated hair follicle with keratin.
*Molluscum bodies - '''key feature''':
*[[Acanthosis]].
**Large cells with abundant granular eosinophilic cytoplasm.
*Budding of epidermis (into dermis).
**Small peripheral nucleus.


Image(s):
DDx:
*[http://commons.wikimedia.org/wiki/File:Molluscum_contagiosum_high_mag.jpg Molluscum contagiosum - high mag. (WC)].
*[[Pilar sheath acanthoma]].
*[http://commons.wikimedia.org/wiki/File:Molluscum_contagiosum_low_mag.jpg Molluscum contagiosum - low magnification (WC)].


Note:  
Image:
*Molluscum bodies vaguely resemble ''[[signet ring cell]]s'' -- but:
*[http://dermpathexpert.com/id90.html Dilated pore of Winer (dermpathexpert.com)].
**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==
==Lichenoid keratosis==
===General===
*[[AKA]] ''lichen planus-like keratosis''.
*Benign sweat duct tumour.
{{Main|Lichenoid keratosis}}
*Eccrine differentiation.
 
*Usually close to lower eyelid.<ref>{{Ref PBoD8|1177}}</ref>
==Granuloma annulare==
{{Main|Granuloma annulare}}


===Microscopic===
==Necrobiosis lipoidica==
Features:<ref>URL: [http://emedicine.medscape.com/article/1059871-diagnosis http://emedicine.medscape.com/article/1059871-diagnosis]. Accessed on: 12 May 2010.</ref>
{{Main|Necrobiosis lipoidica}}
*Proliferation of benign ducts with lined by a bilayer (as in normal sweat ducts) with abnormal architecture:
**Tadpole like appearing ducts.


Image:
==Keloid==
*[http://www.flickr.com/photos/euthman/2329061316/ Syringoma (flickr.com)].
{{Main|Keloid}}


==Inverted follicular keratosis==
==Angiofibroma==
*Benign skin lesion.
:See also: ''[[nasopharyngeal angiofibroma]]''.
*Rare.
:Should '''not''' be confused with ''[[angiokeratoma]]''.
*May mimic [[squamous cell carcinoma]] or basal cell carcinoma.<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>
{{Main|Angiofibroma}}


Images:
==Benign fibrous papule==
*[http://www.flickr.com/photos/euthman/3059309003/ Inverted follicular keratosis - low mag. (flickr.com)].
*[[AKA]] ''fibrous papule''.
*[http://www.flickr.com/photos/euthman/3060145702/ Inverted follicular keratosis - high mag. (flickr.com)].


==Dermal cylindroma==
===General===
===General===
*Benign skin lesion.
*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>
*Should not be confused with ''cylindroma'' ([[adenoid cystic carcinoma]]).
 
===Gross===
*Solitary lesion of the face - '''important'''.<ref name=Ref_Derm505>{{Ref Derm|505}}</ref>
**Usually on the nose.<ref name=pmid18032900/>


===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/>


Images:
DDx:
*[http://commons.wikimedia.org/wiki/File:Dermal_cylindroma_intermed_mag.jpg Dermal cylindroma (WC)].
*[[Angiofibroma]] - not solitary or not on the nose.
*[http://commons.wikimedia.org/wiki/File:Dermal_cylindroma_intermed_mag_deep.jpg Dermal cylindroma - high mag. (WC)].


==Keratoacanthoma==
Note:
*Abbreviated ''KA''.
*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>
*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===
===Images===
*May grow rapidly (weeks or months) then involute.
*[http://www.dermaamin.com/site/histopathology-of-the-skin/58-f/1739-fibrous-papule-angiofibroma-.html Fibrous papule (dermaamin.com)].
*Main DDx is squamous cell carcinoma.
*Exophytic lesion, well-circumscribed.


===Microscopic===
===Sign out===
Features:<ref>{{Ref Klatt|378}}</ref>
<pre>
*Expansion of stratum spinosum - pushing tongue-like downward growth of epidermis into the dermis.
SKIN LESION, CHIN, BIOPSY:
*Keratin collection (keratin plug) at the center of lesion-superficial aspect.
- BENIGN FIBROUS PAPULE.
*Cells have glassy pink cytoplasm.
</pre>
*Minimal/no nuclear atypia.


Image:
==Molluscum contagiosum==
*[http://commons.wikimedia.org/wiki/File:Skin_keratoacanthoma_whole_slide.jpg Keratocanthoma (WC).]
{{Main|Molluscum contagiosum}}


==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 432: Line 397:


==Mastocytosis==
==Mastocytosis==
===General===
{{Main|Mastocytosis}}
*Abundance of mast cells.
*Predominantly in children - if skin only.
 
===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.
*CD117 +ve.


==Ichthyosis==
==Ichthyosis==
Line 461: 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 469: 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 506: Line 436:


==Angiokeratoma==
==Angiokeratoma==
{{Main|Angiokeratoma}}
==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===
*Rare.
*Benign skin lesion.
*May be seen in the context of [[Fabry disease]].<ref name=pmid16403380/> (???)
*Central face - middle age.<ref name=Ref_Derm387>{{Ref Derm|387}}</ref>
*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>
*[[BCC]].
*[[Wart]].


===Microscopic===
===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>
Features:<ref name=Ref_Derm387>{{Ref Derm|387}}</ref>
*Ectatic superficial dermal vessels.
*Keratinocyte of cytologically benign proliferation.
*Overlying hyperkeratosis
*"Squamous eddies" (whorls of keratin).
*Coarse keratohyaline granules.
 
DDx:
*[[Squamous cell carcinoma of the skin]].
*[[Trichilemmoma]].
*[[Seborrheic keratosis]] - has an exophytic component.
 
Images:
*[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://mckeedermpath.com/SPOT%20DIAGNOSIS%20CASE%20474.html Inverted follicular keratosis - several images (mckeedermpath.com)].


Others: (???)
===Sign out===
*Irregular acanthosis.
<pre>
*Longer rete ridges.
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>


Image:
===Microscopic===
*[http://www.pathologyoutlines.com/images/skintumorangiokerat1.jpg Angiokeratoma (pathologyoutlines.com)].
Features:
*Light blue whispy material in the dermis - '''key feature'''.


DDx:
DDx:
*[[Venous lake]].
*Dermal edema.
*[[Digital mucous cyst]].


==Panniculitis==
==Panniculitis==
DDx:
{{Main|Panniculitis}}
*Erythema nodosum.
This is dealt with in the ''[[panniculitis]]'' article.
*Erythema induratum.
 
DDx for panniculitis:
*[[Erythema nodosum]].
*[[Erythema induratum]].
*Self-inflicted trauma.
*Self-inflicted trauma.
*Systemic lupus erythematosus.
*[[Systemic lupus erythematosus]].
*Weird stuff.  
*Weird stuff.


===Erythema nodosum===
=Rare=
Features:<ref name=Ref_PBoD8_1199>{{Ref PBoD8|1199}}</ref>
==Necrotizing fasciitis==
*Common.
:'''''Not''' to be confused with [[nodular fasciitis]]''.
*Assoc. with [[IBD]].
*[[AKA]] ''flesh-eating disease''.
{{Main|Necrotizing fasciitis}}


====Microscopic====
==Porokeratosis==
Features:<ref name=Ref_PBoD8_1199>{{Ref PBoD8|1199}}</ref>
{{Main|Porokeratosis}}
*Expanded (inter-adipocyte cluster) septa.
*Neutrophils.
*Fibrin.


Notes:
==Nevus sebaceous==
*No vasculitis.
*[[AKA]] ''nevus sebaceous of Jadassohn''.
===Erythema induratum===
{{Main|Nevus sebaceous}}
Features:<ref name=Ref_PBoD8_1199>{{Ref PBoD8|1199}}</ref>
*Not common.
*Etiology: unknown.


====Microscopic====
==Nevus lipomatosus superficialis==
Features:<ref name=Ref_PBoD8_1199>{{Ref PBoD8|1199}}</ref>
*Abbreviated ''NLS''.
*Necrotizing granulomatous inflammation.
*[[AKA]] ''nevus lipomatosus cutaneous superficialis'', abbreviated ''NLCS''.
*Necrotizing vasculitis of small/medium sized vessels (early).
*[[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}}
DDx:
*Infection.


=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

Main article: 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

  • Dermatomycosis - intermed. mag. (WC)

  • Dermatomycosis - high mag. (WC)

  • Dermatomycosis - GMS stain - low mag. (WC)

  • Dermatomycosis - GMS stain - high mag. (WC)

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

Main article: Dermal scar

Fibroepithelial polyp

Main article: Fibroepithelial polyp

Actinic keratosis

Main article: 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

Main article: Seborrheic keratosis

Pilomatricoma

Main article: Pilomatricoma

Dermatofibroma

Main article: 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

  • Solar elastosis - intermed. mag. (WC)

  • Solar elastosis - high mag. (WC)

www:

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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

Main article: 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:

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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

Main article: Clear cell acanthoma

Chondrodermatitis nodularis chronica helicis

  • AKA chondrodermatitis nodularis helicis.
  • Abbreviated CNCH.
  • AKA Winkler disease.[13]
Main article: Chondrodermatitis nodularis chronica helicis

Cutaneous calcinosis

  • AKA calcinosis cutis.
Main article: Cutaneous calcinosis

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.
Main article: Lichenoid keratosis

Granuloma annulare

Main article: Granuloma annulare

Necrobiosis lipoidica

Main article: Necrobiosis lipoidica

Keloid

Main article: Keloid

Angiofibroma

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

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

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

Molluscum contagiosum

Main article: 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

Main article: 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.
Main article: Palmar fibromatosis

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

Main article: 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:

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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

Main article: 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.
Main article: Necrotizing fasciitis

Porokeratosis

Main article: Porokeratosis

Nevus sebaceous

  • AKA nevus sebaceous of Jadassohn.
Main article: Nevus sebaceous

Nevus lipomatosus superficialis

  • Abbreviated NLS.
  • AKA nevus lipomatosus cutaneous superficialis, abbreviated NLCS.
  • AKA nevus lipomatosus.[28]
Main article: Nevus lipomatosus superficialis

Bullous disease

Main article: Bullous disease

Cysts

Main article: Dermal 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.
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