Non-malignant skin disease
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 conditions
Classification
- Bullous.
- Interface.
- Nodular & diffuse.
- Spongiotic.
- Vasculitis.
- Perivascular.
- Panniculitis.
- Psoriasiform.
Tabular comparison of inflammatory skin disease (adapted from Brister[1]):
Pattern | Key histologic feature | Subclassifications | Example |
Bullous | "Empty space" | -Subcorneal -Suprabasillar -Subepidermal |
-Pemphigus foliaceus -Pemphigus vulgaris -Dermatitis herpetiformis |
Interface | Inflammation at DE junction | -Vacuolar (minimal) -Lichenoid (band-like) |
-Erythema multiforme -Lichen simplex chronicus (LSC) |
Nodular & diffuse | Nodular & diffuse | ? | |
Spongiotic | Edema between keratinocytes | -Acute -Subacute -Chronic |
-Poison Ivy -Nummular dermatitis -Atopic dermatitis |
Vasculitis | Inflammation of vessel wall | ? | ? |
Perivascular | Inflammation around vessels | ? | ? |
Panniculitis | Inflamm. of SC tissue | -Septal -Nodular |
-? -Erythema nodosum |
Psoriasiform | Epidermal thickening and long rete ridges |
-Regular -Irregular |
-Psoriasis -? |
Notes:
- DE junction = dermal-epidermal junction.
- The "empty space" in bullous disease in situ is filled with fluid.
Psoriasis
General
- Can be subclassified.
DDx:
- Psoriasis vulgaris (most common).
- Psoriatic arthritis.
- Drug-induced.
- Others.
Microscopic
Features:[2]
- Epidermal thickened - as very long rete ridges (described as "test tube-morphology") - key feature.
- Epidermis between rete ridges thin.
Seborrheic dermatitis
General
- Very common.
Microscopic
Features:[3]
- Spongiosis (epidermal edema).
- Acanthosis (epidermal thickening).
- "Follicular lipping" = parakeratosis with neutrophils.
- Perivascular neutrophils and lymphocytes.
Lichen planus
General
Etiology:
- Autoimmune disease, T-cell–mediated.[6]
Clinical:[7]
- 6 Ps: pruritic (itchy), purple, polygonal, planar papules and plaques.
Gross
- Wickham striae = white lines/dots.
- Due to hypergranulosis.
Microscopic
- 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.[10]
DDx:
- Bullous disease, subepithelial vesicular.
Notes:
- Hyperkeratosis and hypergranulosis are not seen in erythema multiforme.
- Colloid bodies = cytoid bodies = Civatte bodies = hyaline bodies = apoptotic bodies.[11]
- DDx: systemic lupus erythematosus, lichen planus, and graft-versus-host disease.
Images:
Lichen sclerosus
Microscopic
Features:[12]
- Subepithelial fibrosis - key feature.
Psoriasis
General
- Chronic skin condition +/- systemic involvement:[13]
- Arthritis.
- Myopathy.
- Enteropathy, e.g. inflammatory bowel disease.
- Syondylitic joint disease (spondylos = vertebrae[14]).
Clinical:
- Auspitz sign = pin-point bleeding on removal of scale.
- Koebner phenomenon = lesions form at site of trauma.
Microscopic
Features:[13]
- Acanthosis + long rete ridges - key feature.
- Parakeratosis.
- Dilated vessels in superficial dermis (give rise to Auspitz sign).
- Spongiform pustules = PMNs in stratum spinosum.
- PMNs in parakeratotic stratum corneum (Munro microabscess).
Other
Squamous cell hyperplasia
General
- Variant of spongiotic dermatitis.[16]
Etiology:[17]
- Pruritus (itchness) -> mechanical trauma -> lichenification (thickened/leathery[18].
Microscopic
Features:[12]
- Acanthosis (epithelial thickening).
- Hyperkeratosis.
Other features:[19]
- Spongiosis (epidermal intercellular edema -- cells appear to have a clear halo around 'em).
- Parakeratosis = retention of nuclei in the stratum corneum.
Images:
Very common
Fibroepithelial polyp
- AKA acrochordon, skin tag.
General
- Benign.
- Older people.
- May be associated with pregnancy, diabetes, intestinal polyposis.[20]
Gross
- Raised skin-coloured lesion.
Image:
Microscopic
Features:
- On a stalk.
- Benign epidermis.
Seborrheic keratosis
- Abbreviated SK.
General
- Benign.
- Most common tumour in older people.[21]
- "Large number" of SKs = paraneoplastic syndrome (Leser–Trélat sign).[22]
Epidemiology:
- Old people.
- Usu. in sun exposed area.[23]
Gross
- "Stuck-on" appearance - raised lesion.
Image(s):
Microscopic
Features:[22]
- 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:
- Seborrheic keratosis - low mag. (WC).
- Seborrheic keratosis - high mag. (WC).
- Seborrheic keratosis - high mag. (dermatlas.org).
- Seborrheic keratosis - low mag. (dermatlas.org).
Verruca vulgaris
General
Notes:
- Related to condyloma acuminatum.
Microscopic
Features:[24]
- Hyperkeratosis (more keratin - thick stratum corneum).
- Hypergranulosis (thicker stratum granulosum).
- Acanthosis (thickening of the stratum spinosum).
- Rete ridges lengthened (~7-10x normal).
- Large blood vessels at the dermal-epidermal junction.
Memory device: there is more of everything - more s. corneum, s. granulosum, s. spinosum, longer rete ridges, more (larger) blood vessels.
Images:
Pilomatricoma
- AKA pilomatrixoma.
General
- Benign skin tumour.
- Most common solid skin tumour of children.[25]
Clinical:
- Hard nodule - calcification.
- +/-Painful. (???)
Treatment:
- Surgical excision.[25]
Microscopic
Features:[26]
- Location: lower dermis/subcutaneous fat; thus, usu. surrounded by connective tissue.
- Sharpy demarcated island of cells.
- Calcification in 75% - with calcium staining (von Kossa).
- Cells:[27]
- Basaloid epithelial cells - have prominent nucleoli.
- Anucleate squamous cells ("ghost cells").
- Giant cell foreign body type granulomas (form in reaction to keratin).
Notes:
- Keratin a prominent feature on cytology - lots of orange stuff.
Images:
- Pilomatrixoma - cytology (bccancer.bc.ca).
- Pilomatrixoma - histology (dermrounds.com).
- Pilomatrixoma - high mag. (WC).
- Pilomatrixoma - intermed. mag. (WC).
DDx:
Dermatofibroma
General
- AKA fibrous histiocytoma.
- Reactive process -- it is not a neoplasm.
- Usually associated with previous trauma.
- In women... usually legs.
Microscopic
Features:[28]
- 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").
- Surrounded by spindle cells (fibroblasts).
- Lack of adnexal structures, i.e. no sweat glands, no hair.
- +/-Epidermal changes - known as "dirty fingers":[29]
- Acanthosis (thickened epithelial layer - specifically thickened stratum spinosum).
- Basal keratinocyte hyperpigmentation.
Images:
DDx:
Subtypes
Like all common things... there are subtypes:[30]
- 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
- Factor XIIIa +ve.
- Usually negative in DFSP.
- CD34 -ve.
- Usually positive in DFSP.
- D2-40 +ve.[33]
- Usually negative in DFSP.
Ezcema
General
- A nebulous thingy.
- Very common.
DDx:
- Contact allergy.
- Drug reaction.
- Food allergy.
Microscopic
Features:[34]
- Spongiosis (epidermal edema); keratinocytes spacing increased - key feature.
- +/-Interdermal vesicles.
- +/-Eosinophils (may suggest Rx reaction).
- Perivascular lymphocytes.
Less common
Molluscum contagiosum
- Etiology: caused by molluscum contagiosum virus.
Microscopic
Features:
- A suprabasilar epidermal lesion consisting of "molluscum bodies", i.e. molluscum bodies are found above the stratum basale.[35]
- Molluscum bodies - key feature:
- Large cells with abundant granular eosinophilic cytoplasm.
- Small peripheral nucleus.
Image(s):
Note:
- Molluscum bodies vaguely resemble signet ring cells -- but:
- Cytoplasm eosinophilic and granular.
- Nucleus usually smaller than in signet ring cell.
- Molluscum bodies are only the epidermis - an uncommon place to find SRCs without finding them elsewhere.
- The granular eosinophilic cytoplasm represents accumulated virons.
Syringoma
General
- Benign sweat duct tumour.
- Eccrine differentiation.
- Usually close to lower eyelid.[36]
Microscopic
Features:[37]
- Proliferation of benign ducts with lined by a bilayer (as in normal sweat ducts) with abnormal architecture:
- Tadpole like appearing ducts.
Image:
Inverted follicular keratosis
- Benign skin lesion.
- Rare.
- May mimic squamous cell carcinoma or basal cell carcinoma.[38]
Images:
- Inverted follicular keratosis - low mag. (flickr.com).
- Inverted follicular keratosis - high mag. (flickr.com).
Dermal cylindroma
General
- Benign skin lesion.
- Should not be confused with cylindroma (adenoid cystic carcinoma).
Microscopic
Features:
- Nests of cells that are surrounded by hyaline (i.e. glassy, eosinophilic, acellular) material.
Images:
Keratoacanthoma
- Abbreviated KA.
- Generally considered to be benign.
- Rare reports of metastases suggesting it may be a form of squamous cell carcinoma.[39]
Clinical
- May grow rapidly (weeks or months) then involute.
- Main DDx is squamous cell carcinoma.
- Exophytic lesion, well-circumscribed.
Microscopic
Features:[40]
- Expansion of stratum spinosum - pushing tongue-like downward growth of epidermis into the dermis.
- Keratin collection (keratin plug) at the center of lesion-superficial aspect.
- Cells have glassy pink cytoplasm.
- Minimal/no nuclear atypia.
Image:
Superficial dermal infiltrates
Discussed in detail by Alsaad and Ghazarian.[41]
Dermal perivascular lymphoeosinophilic infiltration (DPLI)
- Microscopic appearance is just what it is called:
- Lymphocytes and eosinophils around the vessels in the superficial dermis.
DDx:[41]
- Insect bite - classically wedge-shaped.[42]
- Drug reactions.
- Urticarial reactions.
- Prevesicular early stage of bullous pemphigoid.
- HIV related dermatoses.
Notes:
- May superficially resemble cutaneous lymphoma.[42]
Images:
Congenital dermal melanocytosis
- AKA Mongolian spots.
- Classically seen in asian children.
Gross:
- Brown or blue-grey patch in the lumbosacral area.
Mastocytosis
General
- Abundance of mast cells.
- Predominantly in children - if skin only.
Microscopic
Features:[43]
- 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.
- Lymphocyte-like with more cytoplasm that is granular.
- +/-Eosinophils (common).
- +/-Edema - often prominent; gives cells a white halo.
Notes:
- Lymphocyte vs. mast cell:
- Lymphocytes = round; mast cells = ovoid.
Images:
Stains
- Toluidine blue -- highlights the granules.
- CD117 +ve.
Ichthyosis
General
- Comes in different flavours.
- Usu. inherited... thus a pediatric condition.
Clinical:
- Fish scale-like appearance.
Microscopic
Features:[43]
- Thick stratum corneum without basket-weave pattern.
Palmar fibromatosis
General
- AKA Dupuytren's contracture.
Clinical:[44]
- Usually older 60-70s.
- Male > female.
- Associated with:
- Alcohol abuse.
- May be familial.
Microscopic
Features:[45]
- Bland spindle cells in dense collagen.
- No nuclear atypia.
- Giant cells.
- +/-Mitotic figures.
Images:
Angiomyoma
- Do not confuse with angiomyxoma.
General
- Benign.
- Female > male.[47]
Microscopic
Features:
- Well-circumscribed lesion with fascicular architecture.
- Spindle cells/epithelioid cell with moderate eosinophilic (pink) cytoplasm.
- Thick-walled blood vessels. (???)
Images:
Angiokeratoma
General
- Rare.
- May be seen in the context of Fabry disease.[48] (???)
Microscopic
Features:[48]
- Ectatic superficial dermal vessels.
- Overlying hyperkeratosis
Others: (???)
- Irregular acanthosis.
- Longer rete ridges.
Image:
DDx:
Panniculitis
DDx:
- Erythema nodosum.
- Erythema induratum.
- Self-inflicted trauma.
- Systemic lupus erythematosus.
- Weird stuff.
Erythema nodosum
Features:[49]
- Common.
- Assoc. with IBD.
Microscopic
Features:[49]
- Expanded (inter-adipocyte cluster) septa.
- Neutrophils.
- Fibrin.
Notes:
- No vasculitis.
Erythema induratum
Features:[49]
- Not common.
- Etiology: unknown.
Microscopic
Features:[49]
- Necrotizing granulomatous inflammation.
- Necrotizing vasculitis of small/medium sized vessels (early).
DDx:
- Infection.
Bullous disease
Cysts
See also
References
- ↑ Brinster NK (March 2008). "Dermatopathology for the surgical pathologist: a pattern based approach to the diagnosis of inflammatory skin disorders (part I)". Adv Anat Pathol 15 (2): 76–96. doi:10.1097/PAP.0b013e3181664e8d. PMID 18418089.
- ↑ Kumar, Vinay; Abbas, Abul K.; Fausto, Nelson; Aster, Jon (2009). Robbins and Cotran pathologic basis of disease (8th ed.). Elsevier Saunders. pp. 1191. ISBN 978-1416031215.
- ↑ Kumar, Vinay; Abbas, Abul K.; Fausto, Nelson; Aster, Jon (2009). Robbins and Cotran pathologic basis of disease (8th ed.). Elsevier Saunders. pp. 1191. ISBN 978-1416031215.
- ↑ Teichman, JM.; Sea, J.; Thompson, IM.; Elston, DM. (Jan 2010). "Noninfectious penile lesions.". Am Fam Physician 81 (2): 167-74. PMID 20082512.
- ↑ Gupta, R.; Bansal, B.; Singh, S.; Yadav, I.; Gupta, K.; Kudesia, M. (2009). "Lichen planus of uterine cervix - the first report of a novel site of occurrence: a case report.". Cases J 2: 9306. doi:10.1186/1757-1626-2-9306. PMID 20062629.
- ↑ URL: http://emedicine.medscape.com/article/1078327-overview. Accessed on: 11 September 2010.
- ↑ Kumar, Vinay; Abbas, Abul K.; Fausto, Nelson; Aster, Jon (2009). Robbins and Cotran pathologic basis of disease (8th ed.). Elsevier Saunders. pp. 1191. ISBN 978-1416031215.
- ↑ URL: http://emedicine.medscape.com/article/1078327-overview. Accessed on: 11 September 2010.
- ↑ Kumar, Vinay; Abbas, Abul K.; Fausto, Nelson; Aster, Jon (2009). Robbins and Cotran pathologic basis of disease (8th ed.). Elsevier Saunders. pp. 1192. ISBN 978-1416031215.
- ↑ Mitchell, Richard; Kumar, Vinay; Fausto, Nelson; Abbas, Abul K.; Aster, Jon (2011). Pocket Companion to Robbins & Cotran Pathologic Basis of Disease (8th ed.). Elsevier Saunders. pp. 604. ISBN 978-1416054542.
- ↑ URL: http://www.careforumwales.org/cell-carcinoma/histopathologic-terminology.html. Accessed on: 28 August 2011.
- ↑ 12.0 12.1 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. 1065-6. ISBN 0-7216-0187-1.
- ↑ 13.0 13.1 Mitchell, Richard; Kumar, Vinay; Fausto, Nelson; Abbas, Abul K.; Aster, Jon (2011). Pocket Companion to Robbins & Cotran Pathologic Basis of Disease (8th ed.). Elsevier Saunders. pp. 603. ISBN 978-1416054542.
- ↑ URL: http://medical-dictionary.thefreedictionary.com/spondylosis. Accessed on: 28 August 2011.
- ↑ Kumar, Vinay; Abbas, Abul K.; Fausto, Nelson; Aster, Jon (2009). Robbins and Cotran pathologic basis of disease (8th ed.). Elsevier Saunders. pp. 1011. ISBN 978-1416031215.
- ↑ Tadrous, Paul.J. Diagnostic Criteria Handbook in Histopathology: A Surgical Pathology Vade Mecum (1st ed.). Wiley. pp. 296. ISBN 978-0470519035.
- ↑ URL: http://emedicine.medscape.com/article/1123423-overview. Accessed on: 20 August 2010.
- ↑ URL: http://www.medterms.com/script/main/art.asp?articlekey=10131. Accessed on: 20 August 2010.
- ↑ URL: http://emedicine.medscape.com/article/1123423-diagnosis. Accessed on: 20 August 2010.
- ↑ Mitchell, Richard; Kumar, Vinay; Fausto, Nelson; Abbas, Abul K.; Aster, Jon (2011). Pocket Companion to Robbins & Cotran Pathologic Basis of Disease (8th ed.). Elsevier Saunders. pp. 596. ISBN 978-1416054542.
- ↑ URL: http://emedicine.medscape.com/article/1059477-overview#a0199. Accessed on: 26 August 2011.
- ↑ 22.0 22.1 Mitchell, Richard; Kumar, Vinay; Fausto, Nelson; Abbas, Abul K.; Aster, Jon (2011). Pocket Companion to Robbins & Cotran Pathologic Basis of Disease (8th ed.). Elsevier Saunders. pp. 595. ISBN 978-1416054542.
- ↑ URL: http://emedicine.medscape.com/article/1059477-overview. Accessed on: 26 August 2011.
- ↑ URL: http://missinglink.ucsf.edu/lm/DermatologyGlossary/verruca_vulgaris.html. Accessed on: 14 July 2010.
- ↑ 25.0 25.1 http://emedicine.medscape.com/article/1058965-overview
- ↑ http://emedicine.medscape.com/article/1058965-diagnosis
- ↑ http://www.bccancer.bc.ca/HPI/CE/cytotechnology/cytosleuthquiz/nongyne/ngcase02d.htm
- ↑ 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.
- ↑ BD. 13 April 2011.
- ↑ Mills, Stacey E; Carter, Darryl; Greenson, Joel K; Reuter, Victor E; Stoler, Mark H (2009). Sternberg's Diagnostic Surgical Pathology (5th ed.). Lippincott Williams & Wilkins. pp. 51. ISBN 978-0781779425.
- ↑ Abenoza P, Lillemoe T (October 1993). "CD34 and factor XIIIa in the differential diagnosis of dermatofibroma and dermatofibrosarcoma protuberans". Am J Dermatopathol 15 (5): 429–34. PMID 7694515.
- ↑ Goldblum JR, Tuthill RJ (April 1997). "CD34 and factor-XIIIa immunoreactivity in dermatofibrosarcoma protuberans and dermatofibroma". Am J Dermatopathol 19 (2): 147–53. PMID 9129699.
- ↑ Bandarchi B, Ma L, Marginean C, Hafezi S, Zubovits J, Rasty G (March 2010). "D2-40, a novel immunohistochemical marker in differentiating dermatofibroma from dermatofibrosarcoma protuberans". Mod. Pathol. 23 (3): 434–8. doi:10.1038/modpathol.2009.176. PMID 20062007.
- ↑ 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.
- ↑ http://www.missionforvisionusa.org/anatomy/2006/08/what-is-molluscum-contagiosum.html
- ↑ Kumar, Vinay; Abbas, Abul K.; Fausto, Nelson; Aster, Jon (2009). Robbins and Cotran pathologic basis of disease (8th ed.). Elsevier Saunders. pp. 1177. ISBN 978-1416031215.
- ↑ URL: http://emedicine.medscape.com/article/1059871-diagnosis. Accessed on: 12 May 2010.
- ↑ URL: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC475744/. Accessed on: 11 May 2010.
- ↑ Mandrell JC, Santa Cruz D (August 2009). "Keratoacanthoma: hyperplasia, benign neoplasm, or a type of squamous cell carcinoma?". Semin Diagn Pathol 26 (3): 150–63. PMID 20043514.
- ↑ Klatt, Edward C. (2006). Robbins and Cotran Atlas of Pathology (1st ed.). Saunders. pp. 378. ISBN 978-1416002741.
- ↑ 41.0 41.1 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.
- ↑ 42.0 42.1 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.
- ↑ 43.0 43.1 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.
- ↑ URL: http://www.humpath.com/palmar-fibromatosis. Accessed on: 6 January 2011.
- ↑ URL: [1]. Accessed on: 6 January 2011.
- ↑ Wang L, Zhu H (2006). "Clonal analysis of palmar fibromatosis: a study whether palmar fibromatosis is a real tumor". J Transl Med 4: 21. doi:10.1186/1479-5876-4-21. PMC 1488873. PMID 16696857. http://www.biomedsearch.com/nih/Clonal-analysis-palmar-fibromatosis-study/16696857.html.
- ↑ 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.
- ↑ 48.0 48.1 Karen, JK.; Hale, EK.; Ma, L. (2005). "Angiokeratoma corporis diffusum (Fabry disease).". Dermatol Online J 11 (4): 8. PMID 16403380.
- ↑ 49.0 49.1 49.2 49.3 Kumar, Vinay; Abbas, Abul K.; Fausto, Nelson; Aster, Jon (2009). Robbins and Cotran pathologic basis of disease (8th ed.). Elsevier Saunders. pp. 1199. ISBN 978-1416031215.