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]]''.  Inflammatory skin conditions are dealt with in ''[[inflammatory skin disorders]]''.
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]]''.
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=Other=
=Other=
==Lichen simplex chronicus==
==Lichen simplex chronicus==
*Abbreviated ''LSC''.
{{Main|Lichen simplex chronicus}}
*[[AKA]] ''squamous cell hyperplasia''.<ref name=Ref_PBoD1011>{{Ref PBoD8|1011}}</ref>
 
===General===
*May be considered a variant of ''spongiotic dermatitis''.<ref name=Ref_DCHH296>{{Ref DCHH|296}}</ref>; more specifically, some think it is an ''atopic dermatitis'' (which fits in the large ''spongiotic dermatitis'' category).<ref name=Ref_Derm26>{{Ref Derm|26}}</ref>
*It is lumped with the [[psoriasiform dermatitides]].
 
Etiology:<ref>URL: [http://emedicine.medscape.com/article/1123423-overview http://emedicine.medscape.com/article/1123423-overview]. Accessed on: 20 August 2010.</ref>
*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>.
 
===Microscopic===
Features:<ref name=Ref_PBoD1065-6>{{Ref PBoD|1065-6}}</ref>
*Acanthosis (epithelial thickening) - irregular.
*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.
 
DDx:
*[[Prurigo nodularis]] - focal process (nodule or papule).
 
Images:
*[http://commons.wikimedia.org/w/index.php?title=File:Lichen_simplex_chronicus_-_low_mag.jpg LSC - low mag. (WC)].
*[http://commons.wikimedia.org/w/index.php?title=File:Lichen_simplex_chronicus_-_high_mag.jpg LSC - high mag. (WC)].
 
===Sign-out===
<pre>
SKIN, PUNCH BIOPSY:
- LICHEN SIMPLEX CHRONICUS.
- NEGATIVE FOR MALIGNANCY.
</pre>


==Prurigo nodularis==
==Prurigo nodularis==
Line 50: Line 20:


DDx:
DDx:
*[[Lichen simplex chronicus]] - more diffuse process.
*[[Lichen simplex chronicus]] - a more diffuse process, not a raised lesion.
 
===Sign out===
<pre>
SKIN LESION, LEFT CHIN, BIOPSY:
- PRURIGO NODULARIS.
</pre>
 
====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=
=Very common=
==Dermatomycosis==
==Dermatomycosis==
:''Dermatophytosis'' redirects here.
===General===
===General===
*[[microorganisms|Fungal infection]] of skin.
*[[microorganisms|Fungal infection]] of skin.
Line 64: Line 46:
*Microorganisms - '''key feature'''.
*Microorganisms - '''key feature'''.
**Often hyphae (candida) - like twigs of a tree... branching.
**Often hyphae (candida) - like twigs of a tree... branching.
*Perivascular inflammation.
***May be very fragmented in section ~ size of a neutrophil.
*Exocytosis - blood cell infiltrate the epidermis.
*Perivascular inflammation, esp. neutrophils.
*[[Exocytosis]] - blood cell infiltrate the epidermis.


Images:
====Images====
*[http://commons.wikimedia.org/wiki/File:Dermatomycosis_-_intermed_mag.jpg Dermatomycosis - intermed. mag. (WC)].
<gallery>
*[http://commons.wikimedia.org/wiki/File:Dermatomycosis_-_high_mag.jpg Dermatomycosis - high mag. (WC)].
Image:Dermatomycosis_-_intermed_mag.jpg | Dermatomycosis - intermed. mag. (WC)
*[http://commons.wikimedia.org/wiki/File:Dermatomycosis_-_gms_-_low_mag.jpg Dermatomycosis - GMS - low mag. (WC)].
Image:Dermatomycosis_-_high_mag.jpg | Dermatomycosis - high mag. (WC)
*[http://commons.wikimedia.org/wiki/File:Dermatomycosis_-_gms_-_high_mag.jpg Dermatomycosis - GMS stain - 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===
===Stains===
*[[GMS]].
*[[GMS stain]].
*[[PAS]].
*[[PAS-D stain]].


==Cicatrix==
===Sign out===
*[[AKA]] ''scar'', ''dermal scar''.
<pre>
===General===
SKIN, BIOPSY:
*Previous surgery, biopsy, trauma.
- SKIN WITH SUPERFICIAL FUNGAL ORGANISMS CONSISTENT WITH CANDIDA.
 
- REACTIVE CHANGES OF THE EPITHELIUM.
===Microscopic===
</pre>
Features:
*Loss of adnexal structures.
*Dense collagen - fibers run parallel to the dermal-epidermal (DE) junction.
*Loss of dermal papilla.


DDx:
====Micro====
*[[Malignant melanoma]], desmoplastic-neurotropic type.
The sections show skin with a neutrophilic infiltrate in the superficial epidermis.  PAS-D staining demonstrates fungal organisms with a morphology suggestive of candida.
*[[Dermatofibroma]].
*Desmoplastic [[Spitz nevus]].
*Sclerosing [[blue nevus]].


Image:
The epithelium has parakeratosis, acanthosis and spongiosis. No mitotic activity is appreciated. The keratinocytes are moderately enlarged and have evident nucleoli.
*[http://commons.wikimedia.org/wiki/File:ScarHistology.JPG Scar (WC)].


===IHC===
==Cicatrix==
*S100 focal/scattered +ve.
{{Main|Dermal scar}}
**Desmoplastic melanoma strong +ve.
*HMB-45 -ve.
**Sclerosing blue nevus +ve.


==Fibroepithelial polyp==
==Fibroepithelial polyp==
*[[AKA]] ''acrochordon'', ''skin tag''.
{{Main|Fibroepithelial polyp}}
===General===
*Benign.
*Older people.
*May be associated with pregnancy, [[diabetes]], [[intestinal polyposis]].<ref name=Ref_PCPBoD8|596>{{Ref PCPBoD8|596}}</ref>
*Component of ''Birt–Hogg–Dubé syndrome'' - see: ''[[Kidney_tumours#Hereditary_renal_cell_carcinoma|Hereditary RCC]]''.
 
===Gross===
*Raised skin-coloured lesion.
 
Image:
*[http://commons.wikimedia.org/wiki/File:Skintagblemish.jpg Skin tag (WC)].
 
===Microscopic===
Features:
*On a stalk / epithelium on three sides.
*Benign epidermis.
 
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>


==Actinic keratosis==
==Actinic keratosis==
:''Bowenoid actinic keratosis'' redirects to here.
{{Main|Actinic keratosis}}
*Abbreviated ''AK''.
*[[AKA]] solar keratosis.{{fact}}


==Actinic cheilitis==
===General===
===General===
Clinical:
*[[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>
*Yellow-brown scaly, patches.
*Sandpaper sensation - on touching.
 
Risk factors:<ref name=Ref_PBoD8_1180>{{Ref PBoD8|1180}}</ref>  
*Sun exposure.
*Immune suppression (e.g. organ transplant recipients).


===Microscopic===
===Microscopic===
Features:<ref>URL: [http://emedicine.medscape.com/article/1099775-workup#a0723 http://emedicine.medscape.com/article/1099775-workup#a0723]. Accessed on: 1 September 2011.</ref>
:See ''[[actinic keratosis]]''.
*Epidermal nuclear atypia:
**Variation is size, shape and staining.
***Nuclear enlargement - '''key feature'''.
****Should involve the basal layer.
*Abnormal epidermal architecture:
**Palisading.{{Fact}}
*+/-Parakeratosis.
*+/-Irregular acanthosis.


Note:
===Sign out===
*May be full thickness - known as ''bowenoid actinic keratosis''.<ref name=pmid19515076>{{Cite journal  | last1 = Bagazgoitia | first1 = L. | last2 = Cuevas | first2 = J. | last3 = Juarranz | first3 = A. | title = Expression of p53 and p16 in actinic keratosis, bowenoid actinic keratosis and Bowen's disease. | journal = J Eur Acad Dermatol Venereol | volume = 24 | issue = 2 | pages = 228-30 | month = Feb | year = 2010 | doi = 10.1111/j.1468-3083.2009.03337.x | PMID = 19515076 }}</ref>
<pre>
 
LESION, LOWER LIP, BIOPSY:  
DDx:
- ACTINIC CHEILITIS.
*[[Bowen's disease]] - full thickness involvement - with involvement of adnexal epithelium and follicular epithelium.<ref name=pmid19515076/>
- SOLAR ELASTOSIS.
*[[Paget disease of the breast]].
</pre>
*[[Squamous cell carcinoma]].


Images:
====Micro====
*[http://commons.wikimedia.org/wiki/File:Actinic_Keratosis,_H%26E.jpg Actinic keratosis (WC)].
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.
*[http://commons.wikimedia.org/wiki/File:SkinTumors-P5280065.JPG Actinic keratosis (WC)].
*[http://commons.wikimedia.org/wiki/File:SkinTumors-P5280055.JPG Actinic keartosis (WC)].
*[http://commons.wikimedia.org/wiki/File:Bowenoid_actinic_keratosis_-_high_mag.jpg Bowenoid actinic keratosis - high mag. (WC)].
*[http://commons.wikimedia.org/wiki/File:Bowenoid_actinic_keratosis_-_very_high_mag.jpg Bowenoid actinic keratosis - very high mag. (WC)].


==Seborrheic keratosis==
==Seborrheic keratosis==
*Abbreviated ''SK''.
{{Main|Seborrheic keratosis}}
===General===
*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:
*Old people.
*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===
*"Stuck-on" appearance - raised lesion.
 
Image(s):
*[http://www.dermatlas.org/derm/IndexDisplay.cfm?ImageID=91774460 SK - gross image (dermatlas.org)].
 
===Microscopic===
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)].


==Pilomatricoma==
==Pilomatricoma==
*[[AKA]] ''calcifying epithelioma of Malherbe''<ref>{{Ref Derm|387}}</ref>, [[AKA]] ''pilomatrixoma''.
{{Main|Pilomatricoma}}
===General===
*Benign skin tumour.
*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>
*CTNNB1 gene mutation important in pathogenesis.<ref name=Ref_PCPBoD8_597>{{Ref PCPBoD8|597}}</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===
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>
*Lower dermis/subcutaneous adipose lesion; thus, usu. surrounded by connective tissue.
**Sharpy demarcated island of cells.
**Calcification in 75% - with calcium staining (von Kossa).
*Cells:<ref>[http://www.bccancer.bc.ca/HPI/CE/cytotechnology/cytosleuthquiz/nongyne/ngcase02d.htm http://www.bccancer.bc.ca/HPI/CE/cytotechnology/cytosleuthquiz/nongyne/ngcase02d.htm]</ref>
**Basaloid epithelial cells - have prominent nucleoli.
**Anucleate squamous cells ("ghost cells").
**Giant cell foreign body type [[granulomas]] (form in reaction to keratin).
 
Notes:
*Keratin a prominent feature on cytology - lots of orange stuff.
*May ossify.
 
Images:
*[http://www.bccancer.bc.ca/HPI/CE/cytotechnology/cytosleuthquiz/nongyne/ngcase02.htm Pilomatrixoma - cytology (bccancer.bc.ca)].
*[http://www.dermrounds.com/photo/1980062:Photo:431 Pilomatrixoma - histology (dermrounds.com)].
*[http://en.wikipedia.org/wiki/File:Pilomatrixoma_-_high_mag.jpg Pilomatrixoma - high mag. (WC)].
*[http://en.wikipedia.org/wiki/File:Pilomatrixoma_-_intermed_mag.jpg Pilomatrixoma - intermed. mag. (WC)].
 
DDx:
*[[Epidermal inclusion cyst]].


==Dermatofibroma==
==Dermatofibroma==
*Abbreviated ''DF''.
{{Main|Dermatofibroma}}
===General===
*AKA ''fibrous histiocytoma''.
*Reactive process -- it is ''not'' a neoplasm.
*Usually associated with previous trauma.
**In women... usually legs.
 
===Microscopic===
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:
*[http://missinglink.ucsf.edu/lm/DermatologyGlossary/dermatofibroma.html Dermatofibroma (ucsf.edu)].
*[http://www.pacificderm.org/newsflashcpcapril04.html DF - several images (pacificderm.org)].
 
DDx:
*[[Dermatofibrosarcoma protuberans]] (DFSP).
*[[Neurofibroma]].
*[[Blue nevus]].
*[[Melanoma]], esp. desmoplastic neurotropic-type.
 
====Subtypes====
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.
=====Cellular dermatofibroma=====
Features:
*High cell density in the dermis - "blue" at low power.
*Collagen bundles - '''key feature'''.
 
Images:
*[http://www.surgicalpathologyatlas.com/glfusion/mediagallery/media.php?f=0&sort=0&s=20080802171836877 Cellular dermatofibroma (surgicalpathologyatlas.com)].
*[http://www.dermpedia.org/node/2292 Cellular dermatofibroma (dermpedia.org)].<ref>URL: [http://www.dermpedia.org/case/cellular-dermatofibroma-mimicking-dermatofibrosarcoma-protuberans#  http://www.dermpedia.org/case/cellular-dermatofibroma-mimicking-dermatofibrosarcoma-protuberans#]. Accessed on: 4 February 2012.</ref>
 
===IHC===
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==
==Ezcema==
Line 324: Line 146:
===Microscopic===
===Microscopic===
Features:<ref>{{Ref Derm|76}}</ref>
Features:<ref>{{Ref Derm|76}}</ref>
*Folliculitis:<ref name=Ref_Derm77>{{Ref Derm|77}}</ref>
**[[Neutrophil]]s around hair follicle and infiltrate into it - including the follicular canal.
*Epidermal invagination ''or'' cyst at site of a hair follicle - contains:
*Epidermal invagination ''or'' cyst at site of a hair follicle - contains:
**Sebum.
**Sebum.
Line 331: Line 155:
#Open comedones ("blackheads") - no extension to epidermal surface.
#Open comedones ("blackheads") - no extension to epidermal surface.
#Closed comedones ("whiteheads") - to epidermal surface have wide opening.
#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://www.dermnet.com/images/Acne-Histology/picture/4069 Acne (dermnet.com)].
*[http://www.dermnet.com/images/Acne-Histology/picture/4069 Acne (dermnet.com)].


=Very common - viral=
==Solar elastosis==
==Verruca vulgaris==
*[[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===
*[[AKA]] common wart.
*Very common.
*Etiology - [[HPV]].
*Caused by sun exposure - specifically UV light.<ref name=pmid20802019>{{Cite journal  | last1 = Thomas | first1 = NE. | last2 = Kricker | first2 = A. | last3 = From | first3 = L. | last4 = Busam | first4 = K. | last5 = Millikan | first5 = RC. | last6 = Ritchey | first6 = ME. | last7 = Armstrong | first7 = BK. | last8 = Lee-Taylor | first8 = J. | last9 = Marrett | first9 = LD. | title = Associations of cumulative sun exposure and phenotypic characteristics with histologic solar elastosis. | journal = Cancer Epidemiol Biomarkers Prev | volume = 19 | issue = 11 | pages = 2932-41 | month = Nov | year = 2010 | doi = 10.1158/1055-9965.EPI-10-0686 | PMID = 20802019 }}</ref>
**Severity correlated with cumulative exposure to UV light..<ref name=pmid17204514/>
*Often co-localized with skin cancers - as UV light is risk factor for skin cancers.<ref name=pmid17204514 >{{Cite journal  | last1 = Karagas | first1 = MR. | last2 = Zens | first2 = MS. | last3 = Nelson | first3 = HH. | last4 = Mabuchi | first4 = K. | last5 = Perry | first5 = AE. | last6 = Stukel | first6 = TA. | last7 = Mott | first7 = LA. | last8 = Andrew | first8 = AS. | last9 = Applebaum | first9 = KM. | title = Measures of cumulative exposure from a standardized sun exposure history questionnaire: a comparison with histologic assessment of solar skin damage. | journal = Am J Epidemiol | volume = 165 | issue = 6 | pages = 719-26 | month = Mar | year = 2007 | doi = 10.1093/aje/kwk055 | PMID = 17204514 }}</ref>
*Benign.
 
===Microscopic===
Features:
*Grey, spaghetti-like material in the superficial dermis.
 
DDx:
*[[Actinic keratosis]].
*[[Basal cell carcinoma]].
*[[Squamous cell carcinoma of the skin|Squamous cell carcinoma]].
 
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====
<gallery>
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)].


Notes:
===Sign out===
*Related to [[condyloma acuminatum]].
<pre>
SKIN, RIGHT CHEEK, RE-EXCISION:
- DERMAL SCAR.
- EXTENSIVE SOLAR ELASTOSIS.
</pre>
 
=====Prominent blood vessels=====
<pre>
SKIN LESION, LEFT CHEEK, BIOPSY:
- SKIN WITH SOLAR ELASTOSIS AND PROMINENT SMALL BLOOD VESSELS.
</pre>
 
<pre>
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}}


==Verruca plana==
==Verruca plana==
Line 369: Line 238:
*Viral keratohyaline.
*Viral keratohyaline.
*Koilocytes.
*Koilocytes.
*Acanthosis - yet flat surface and base.
*[[Acanthosis]] - yet flat surface and base.


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


=Less common=
=Less common=
==Clear cell acanthoma==
==Chronic folliculitis==
:''Folliculitis'' redirect here.
===General===
===General===
*Benign.
*Common.
*Elderly.
*Infrequently biopsied.
*Classically on the leg.<ref name=pmid18583817>{{Cite journal  | last1 = Akin | first1 = FY. | last2 = Ertam | first2 = I. | last3 = Ceylan | first3 = C. | last4 = Kazandi | first4 = A. | last5 = Ozdemir | first5 = F. | title = Clear cell acanthoma: new observations on dermatoscopy. | journal = Indian J Dermatol Venereol Leprol | volume = 74 | issue = 3 | pages = 285-7 | month =  | year =  | doi =  | PMID = 18583817 | URL = http://www.ijdvl.com/text.asp?2008/74/3/285/41396 }}</ref>
 
*Rare.
===Gross===
*Clinically not distinct.
*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>
**Suspected clinically in only ~3% of cases.<ref name=pmid20931670>{{Cite journal  | last1 = Morrison | first1 = LK. | last2 = Duffey | first2 = M. | last3 = Janik | first3 = M. | last4 = Shamma | first4 = HN. | title = Clear cell acanthoma: a rare clinical diagnosis prior to biopsy. | journal = Int J Dermatol | volume = 49 | issue = 9 | pages = 1008-11 | month = Sep | year = 2010 | doi =  | PMID = 20931670 }}</ref>
 
DDx gross:
*[[Melanocytic lesion]]s.


===Microscopic===
===Microscopic===
Features:<ref>URL: [http://www.drmihm.com/cases/case.cfm?CaseID=45 http://www.drmihm.com/cases/case.cfm?CaseID=45]. Accessed on: 7 February 2012.</ref>
Features:
*Psoriasiform pattern - epidermal thickening (acanthosis).
*Inflammation around the hair follicle - '''key feature'''.
*Keratinocytes:
**Lymphocytes - usu. predominant.
**Pale or light pink cytoplasm (when compared to surrounding non-lesional keratinocytes).
*+/-Chronic changes:
**Separated from one another (spongiosis).
**[[Acanthosis]].
*+/-Stratum corneum [[neutrophil]]s.
**Hyperkeratosis.
**Hypergranulosis.


DDx:
DDx:
*[[Psoriasis vulgaris]].
*[[Acne vulgaris]].


Images:
===Sign out===
*[http://www.drmihm.com/cases/casefigure.cfm?figID=906&CaseID=45 CCA (drmihm.com)].
<pre>
*[http://www.dermatlas.com/derm/IndexDisplay.cfm?ImageID=-327718365 CCA - low mag. (dermatlas.com)].
SKIN LESION, UPPER ARM, BIOPSY:
*[http://www.dermatlas.com/derm/IndexDisplay.cfm?ImageID=546460717 CCA - high mag. (dermatlas.com)].
- CHRONIC FOLLICULITIS WITH SECONDARY SURFACE CHANGES.
</pre>


==Chondrodermatitis nodularis chronica helicis==
====Micro====
*[[AKA]] ''chondrodermatitis nodularis helicis''.
The sections show hair-bearing skin with abundant lymphocytes around and within the hair follicle wall.  
*Abbreviated ''CNCH''.
===General===
*Tender/painful - '''key clinical feature'''.
*Typically right [[ear]] - people more often sleep on this one.<ref name=pmid17879469>{{Cite journal  | last1 = Devani | first1 = A. | last2 = Barankin | first2 = B. | title = Dermacase. Chondrodermatitis nodularis  chronica helicis. | journal = Can Fam Physician | volume = 53 | issue = 5 | pages = 821, 837 | month = May | year = 2007 | doi =  | PMID = 17879469 }}</ref>
*Usually >40 years old.


Etiology:
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.
*Trauma/mechanical.


Clinical DDx:<ref name=pmid17879469/>
There are no granulomas.
*[[BCC]].
*[[SCC]].


===Microscopic===
==Clear cell acanthoma==
Features:<ref name=pmid17879469/>
{{Main|Clear cell acanthoma}}
*Dermal inflammation.
*Epithelial hyperlasia.
*Fibrosis.
*Cartilaginous pathology:
**Perichondrial inflammation  - '''key feature'''.
**Perichondrial disruption.
**+/-Necrosis.
**+/-Hemorrhage.


Images:
==Chondrodermatitis nodularis chronica helicis==
*[http://www.dermpedia.org/case/chondrodermatitis-nodularis-chronica-helicis CNCH (dermpedia.org)].
*[[AKA]] ''chondrodermatitis nodularis helicis''.
*[http://www.surgicalpathologyatlas.com/glfusion/mediagallery/media.php?s=20080802171837514 CNCH (surgicalpathologyatlas.com)].
*Abbreviated ''CNCH''.
*[http://dermatlas.med.jhmi.edu/derm/indexDisplay.cfm?ImageID=2140701395 CNCH (dermatlas.med.jhmi.edu)].
*[[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}}


==Cutaneous calcinosis==
==Cutaneous calcinosis==
*[[AKA]] ''calcinosis cutis''.
*[[AKA]] ''calcinosis cutis''.
===General===
{{Main|Cutaneous calcinosis}}
*Benign in itself; underlying cause may not be benign.
*May be a [[scrotum|scrotal]] lesion - known as ''scrotal calcinosis''.<ref name=pmid20178701>{{Cite journal  | last1 = Dubey | first1 = S. | last2 = Sharma | first2 = R. | last3 = Maheshwari | first3 = V. | title = Scrotal calcinosis: idiopathic or dystrophic? | journal = Dermatol Online J | volume = 16 | issue = 2 | pages = 5 | month =  | year = 2010 | doi =  | PMID = 20178701 }}</ref>
 
Subtypes:<ref name=emed>URL: [http://emedicine.medscape.com/article/1103137-overview http://emedicine.medscape.com/article/1103137-overview]. Accessed on: 21 September 2011.</ref>
#Dystrophic - due to death of cells; may be related to a tumour.
#Metastatic - due to chronic renal failure; hyperkalemia; paraneoplastic phenomenon.
#Iatrogenic - post surgical.
#Idiopathic.
 
===Microscopic===
Features:
*Dermal calcification:
**Acellular purple blobs on [[H&E]].
***+/-Artefactual tearing of surrounding tissue due to processing (cutting).
***+/-Small artefactual lines ~1-2 micrometers due to processing (cutting).
**Usu. well-circumscribed.
 
Images:
*[http://nelspruit-histopath.blogspot.com/2010/12/skin-calcinosis-cutis.html Calcinosis cutis (blogspot.com)].


==Dilated pore of Winer==
==Dilated pore of Winer==
===General===
===General===
*Benign.
*Benign.
*Looks like zit.
*Looks like a zit.


===Microscopic===
===Microscopic===
Features:<ref name=Ref_WMSP486>{{Ref WMSP|486}}</ref>
Features:<ref name=Ref_WMSP486>{{Ref WMSP|486}}</ref>
*Dilated hair follicle with keratin.
*Dilated hair follicle with keratin.
*Acanthosis.
*[[Acanthosis]].
*Budding of epidermis (into dermis).
*Budding of epidermis (into dermis).
DDx:
*[[Pilar sheath acanthoma]].
Image:
*[http://dermpathexpert.com/id90.html Dilated pore of Winer (dermpathexpert.com)].


==Lichenoid keratosis==
==Lichenoid keratosis==
*[[AKA]] ''lichen planus-like keratosis''.
*[[AKA]] ''lichen planus-like keratosis''.
===General===
{{Main|Lichenoid keratosis}}
*Caucasians - middle age or older.
 
Clinical DDx:<ref name=Ref_Derm346>{{Ref Derm|346}}</ref>
*[[BCC]], [[SCC]], melanocytic neoplasm.
 
===Microscopic===
Features:<ref name=Ref_Derm347>{{Ref Derm|347}}</ref>
*Hyperkeratosis.
*Parakeratosis.
*Band of inflammatory cells at DE junction (lichenoid inflammation).
*Dead keratinocytes (Civatte bodies).
*Dermal melanophages.
 
DDx:
*[[Lichen planus]] - need clinical correlation (mucosal lesions).
*[[Drug reaction]].
*[[Cutaneous T-cell lymphoma]].
*Regressed melanocytic lesion.
 
Images:
*[http://www.dermpathexpert.com/id57.html Lichenoid keratosis (dermpathexpert.com)].


==Granuloma annulare==
==Granuloma annulare==
===General===
{{Main|Granuloma annulare}}
*Benign and self-limited condition.
*Etiology unknown - may be assoc. with trauma.<ref name=Ref_Derm51>{{Ref Derm|51}}</ref>
 
===Gross===
*Typically extremities - usu. arms and hands.<ref name=Ref_Derm51>{{Ref Derm|51}}</ref>
 
===Microscopic===
Features:<ref name=Ref_WMSP478>{{Ref WMSP|478}}</ref>
*Dermal palisading [[granuloma]] - typically superficial-to-mid dermis - surrounds:
**Necrotic collagen - '''key feature'''.
***Nuclei "missing" - have undergone karyolysis.
**Mucin - important.
***Loose/pale, paucicellular, eosinophilic.
*Chronic inflammatory cells.
 
Notes:
#There may be multiple small foci with intervening normal dermis.<ref name=Ref_Derm51>{{Ref Derm|51}}</ref>
#Granuloma annulare can be subclassified into ''subcutaneous'' and ''interstitial''.
#Histomorphologically similar to ''[[Rheumatoid nodule]].
 
DDx:
*[[Necrobiosis lipoidica]] - little mucin, no normal dermis between foci,<ref name=Ref_Derm51>{{Ref Derm|51}}</ref> plasma cells - common,<ref name=dermnetnz_nl>URL: [http://dermnetnz.org/pathology/necrobiosis-lipoidica-path.html http://dermnetnz.org/pathology/necrobiosis-lipoidica-path.html]. Accessed on: 24 January 2012.</ref> may involve the fat - tend to be deeper.
*[[Rheumatoid nodule]] - has fibrin in the core of the granuloma (instead of mucin).<ref name=Ref_Derm52>{{Ref Derm|52}}</ref>
*[[Epithelioid sarcoma]] - esp. if the lesion appears to be mid-to-deep dermis.
 
Images:
*WC:
**[http://commons.wikimedia.org/wiki/File:Granuloma_annulare_-_add_-_intermed_mag.jpg Granuloma annulare - intermed. mag. (WC)].
**[http://commons.wikimedia.org/wiki/File:Granuloma_annulare_-_high_mag.jpg Granuloma annulare - high mag. (WC)].
**[http://commons.wikimedia.org/wiki/File:Granuloma_annulare_-_add_-_high_mag.jpg Granuloma annular - palisaded granuloma - high mag. (WC)].
*www:
**[http://www.dermaamin.com/site/histopathology-of-the-skin/61-i/1813-interstitial-granuloma-annulare-.html Granuloma annulare (dermaamin.com)].
 
===Stains===
*Alcian blue +ve (mucin).<ref name=Ref_Derm51>{{Ref Derm|51}}</ref>


==Necrobiosis lipoidica==
==Necrobiosis lipoidica==
===General===
{{Main|Necrobiosis lipoidica}}
Associated with:
*[[Diabetes mellitus]] - known as ''necrobiosis lipoidica diabeticorum''.
*[[Rheumatoid arthritis]].
 
===Microscopic===
Features:<ref name=Ref_Derm51>{{Ref Derm|51}}</ref>
*Dermal palisading [[granuloma]] around:
**Necrotic collagen - '''key feature'''.
***Nuclei "missing" - have undergone karyolysis.
*Little mucin, no normal dermis between foci.
*Plasma cells - common.<ref name=dermnetnz_nl>URL: [http://dermnetnz.org/pathology/necrobiosis-lipoidica-path.html http://dermnetnz.org/pathology/necrobiosis-lipoidica-path.html]. Accessed on: 24 January 2012.</ref>
*May involve adipose tissue.
 
DDx:
*[[Granuloma annulare|Granuloma a'''nn'''ulare]] - '''m'''ore '''m'''ucin, normal dermis between foci,<ref name=Ref_Derm51>{{Ref Derm|51}}</ref> plasma cells uncommon,<ref name=dermnetnz_nl/> no fat involvement - usu. more superficial.
*[[Rheumatoid nodule]].
 
Images:
*[http://dermatology.cdlib.org/103/NYU/case_presentations/042004n10.html Necrobiosis lipoidica (dermatology.cdlib.org)].
*[http://www.drmihm.com/cases/case.cfm?CaseID=53 Necrobiosis lipoidica (drmihm.com)].
*[http://dermnetnz.org/pathology/necrobiosis-lipoidica-path.html Necrobiosis lipoidica (dermnetnz.org)].


==Keloid==
==Keloid==
*''Hypertrophic scar'' redirects to this section.
{{Main|Keloid}}
===General===
*Sites of previous trauma/surgery, esp. in dark skinned individuals.<ref name=Ref_WMSP492>{{Ref WMSP|492}}</ref>
 
===Microscopic===
Features:<ref name=Ref_WMSP492>{{Ref WMSP|492}}</ref>
*Thick collagen bundles - surrounded by paler staining fibroblasts - '''key feature'''.
*Lesion replaces adnexal structures, e.g. hair, sweat glands.
 
DDx:
*Hypertrophic scar.
 
NB:
*'''Reported as "keloidal-type collagen"'''; the clinician decides between ''hypertrophic scar'' and ''keloid''.
 
Images:
*[[WC]]:
**[http://commons.wikimedia.org/wiki/File:Keloid_-_add_-_low_mag.jpg Keloid - low mag. (WC)].
**[http://commons.wikimedia.org/wiki/File:Keloid_-_add_-_intermed_mag.jpg Keloid - intermed. mag. (WC)].
**[http://commons.wikimedia.org/wiki/File:Keloid_-_high_mag.jpg Keloid - high mag. (WC)].
*www:
**[http://missinglink.ucsf.edu/lm/DermatologyGlossary/keloids.html Keloid (ucsf.edu)].


==Angiofibroma==
==Angiofibroma==
:See also: ''[[nasopharyngeal angiofibroma]]''.
:See also: ''[[nasopharyngeal angiofibroma]]''.
:Should '''not''' be confused with ''[[angiokeratoma]]''.
:Should '''not''' be confused with ''[[angiokeratoma]]''.
:''Fibrous papule'' redirects here.
{{Main|Angiofibroma}}
 
==Benign fibrous papule==
*[[AKA]] ''fibrous papule''.
 
===General===
===General===
*May be seen in the context of [[tuberous sclerosis]] - especially "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>
*Solitary lesions in adults are known as ''fibrous papules'' and classically arise on the nose.<ref name=Ref_Derm505>{{Ref Derm|505}}</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 593: 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.


==Superficial dermal infiltrates==
==Superficial dermal infiltrates==
Line 650: 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:
*www:
**[http://www.jameswpattersonmd.com/case_studies/index.cfm?CFID=387434 Mastocytosis - low res. (jameswpattersonmd.com)].
**[http://path.upmc.edu/cases/case366.html Mastocytosis - bone marrow - several images (upmc.edu)].
*[[WC]]:
**[http://commons.wikimedia.org/wiki/File:Mastocytosis_-_high_mag.jpg Mastocytosis - high mag. (WC)].
**[http://commons.wikimedia.org/wiki/File:Mastocytosis_-_cropped_-_very_high_mag.jpg Mastocytosis - very high mag. (WC)].
**[http://path.upmc.edu/cases/case409.html Systemic mastocytosis - several images (upmc.edu)].
 
===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 708: Line 415:


==Palmar fibromatosis==
==Palmar fibromatosis==
{{Main|Fibromatosis}}
*[[AKA]] ''Dupuytren's contracture''.
===General===
*[[AKA]] ''Dupuytren disease''.
*[[AKA]] Dupuytren's contracture.
{{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 746: 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 791: Line 459:
*[[Squamous cell carcinoma of the skin]].
*[[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==
==Focal cutaneous mucinosis==
Line 824: Line 503:
:'''''Not''' to be confused with [[nodular fasciitis]]''.
:'''''Not''' to be confused with [[nodular fasciitis]]''.
*[[AKA]] ''flesh-eating disease''.
*[[AKA]] ''flesh-eating disease''.
===General===
{{Main|Necrotizing fasciitis}}
*High mortality.
*May be diagnosed at [[frozen section]].<ref name=pmid9386043>{{Cite journal  | last1 = Majeski | first1 = J. | last2 = Majeski | first2 = E. | title = Necrotizing fasciitis: improved survival with early recognition by tissue biopsy and aggressive surgical treatment. | journal = South Med J | volume = 90 | issue = 11 | pages = 1065-8 | month = Nov | year = 1997 | doi =  | PMID = 9386043 }}</ref>
*Classically associated with ''Group A streptococcus''.
 
Treatment:
*Operative debridement.
 
===Microscopic===
Features:
*Necrosis of fascia - '''key feature'''.<ref name=pmid15735411>{{Cite journal  | last1 = Wong | first1 = CH. | last2 = Wang | first2 = YS. | title = The diagnosis of necrotizing fasciitis. | journal = Curr Opin Infect Dis | volume = 18 | issue = 2 | pages = 101-6 | month = Apr | year = 2005 | doi =  | PMID = 15735411 | URL = http://www.sepeap.org/archivos/pdf/9859.pdf }}</ref>
**[[PMN]]s and necrotic debris (amorphous grey or pink material).
 
Note:
*Fat lobules between septae may be normal.
 
DDx:
*[[Cellulitis]].
 
Images:
*[http://commons.wikimedia.org/wiki/File:Necrotizing_fasciitis_-_intermed_mag.jpg Necrotizing fasciitis - intermed. mag. (WC)].
*[http://commons.wikimedia.org/wiki/File:Necrotizing_fasciitis_-_high_mag.jpg Necrotizing fasciitis - high mag. (WC)].


==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.
 
Images:
*[[WC]]:
**[http://commons.wikimedia.org/wiki/File:Porokeratosis_-_intermed_mag.jpg Porokeratosis - intermed. mag. (WC)].
**[http://commons.wikimedia.org/wiki/File:Porokeratosis_-_very_high_mag.jpg Porokeratosis - very high mag. (WC)].


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


==Nevus lipomatosus superficialis==
==Nevus lipomatosus superficialis==
*Abbreviated ''NLS''.
*Abbreviated ''NLS''.
===General===
*[[AKA]] ''nevus lipomatosus cutaneous superficialis'', abbreviated ''NLCS''.
*Rare.
*[[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>
*Congenital.
{{Main|Nevus lipomatosus superficialis}}
*Usually lower trunk or gluteal region.<ref>{{Cite journal  | last1 = Jones | first1 = EW. | last2 = Marks | first2 = R. | last3 = Pongsehirun | first3 = D. | title = Naevus superficialis lipomatosus. A clinicopathological report of twenty cases. | journal = Br J Dermatol | volume = 93 | issue = 2 | pages = 121-33 | month = Aug | year = 1975 | doi =  | PMID = 1235780 }}</ref>
 
===Microscopic===
Features:<ref name=pmid19495497>{{Cite journal  | last1 = Yap | first1 = FB. | title = Nevus lipomatosus superficialis. | journal = Singapore Med J | volume = 50 | issue = 5 | pages = e161-2 | month = May | year = 2009 | doi =  | PMID = 19495497 | URL = http://smj.sma.org.sg/5005/5005cr3.pdf }}</ref>
*Benign adipose tissue in the superficial dermis.
 
DDx:
*[[Lipoma]].
 
Image:
*[http://www.dermaamin.com/site/images/histo-pic/n/nevus-lipomatosus-superficialis/nevus-lipomatosus-superficialis1.jpg NLS (dermamin.com)].<ref>URL: [http://www.dermaamin.com/site/histopathology-of-the-skin/66-n/1971-nevus-lipomatosus-superficialis----.html http://www.dermaamin.com/site/histopathology-of-the-skin/66-n/1971-nevus-lipomatosus-superficialis----.html]. Accessed on: 7 March 2012.</ref>


=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.