pathology
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Sebaceous hyperplasia Clinical features •This is common and presents as single or commonly multiple, yellow dome-shaped umbilicated papule(s) (1-2 mm diameter) on face of the elderly but may occur on the chest, the caruncle, external genitalia & areola •M>F •Increased incidence with cyclosporine Histological features •Lobules drain into a dilated follicle •Lobules are increased in number but do not…
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•The late Bernie Ackerman classified acquired melanocytic nevi into Miescher nevus which most commonly occurs on the face and Unna nevus which generally presents on or below the neck •Miescher nevus is typically dome-shaped •In Miescher nevus, the nevus is generally dermal, wedge shaped & extends into the reticular dermis •Unna nevus presents as an exophytic, light to dark brown, polypoid,…
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The term is used when 2 or more nevus subtypes are present in a a single lesion (phenotypic heterogeneity). It is mostly seen in commmon nevi, less often in congenital nevus, dysplastic nevus & Spitz nevus. The most commonly encountered combination is with deep penetrating nevus but combinations with blue & cellular blue nevi &…
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This is a very rare tumor with only 31 cases documented in the literature. It consists of an admixture of matricial cells & usually, heavily pigmented dendritic cells although in some cases, eithelioid melanocytes may also be present. Clinical features •Purple-black papulonodule (O.2-2.5 (mean 0.8 cm) •Elderly (28-92 (median age 70) •M>F •Sun damaged skin…
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All of these lesions are thought to arise as a consequence of impaired migration of melanomcytes from the neural crest to the epidermis. Lumbosacral congenital dermal melanocytosis (Mongolian blue spot, slate gray nevus) Congenital dermal melanocytosis presents as an often large, slate blue colored lesion most often affecting the lumbar & sacral-gluteal region but can…
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Halo nevus, also known as regressing nevus, Sutton’s nevus and leukoderma acquisitum centrifugum represents regression and in usually associated with a common/banal nevus. However it may also be seen with congenital nevus, dysplastic nevus, Spitz nevus, blue nevus and importantly with melanoma. A halo phenomenon may also be seen with a banal/common nevus in the…
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Balloon cell nevus represents the benign counterpart of balloon cell melanoma. Clinical features . Most common in first 3 decades . Head & neck > trunk & extremities although any site may be affected including the mucosae . No sex predilection Histological features .Balloon cell change is most often seen in banal melanocytic nevi but…
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Clinical features •Fairly common affecting 0.6-1.6% of the population •Classified into small (1.5 cm or less in diameter, medium (1.5-20 cm) & large/giant/bathing trunk (>20 cm) •Present at birth & sometimes multiple (satellite lesions) .May be associated with hypertrichosis •Trunk & legs>head & neck, feet & hands . Development of a halo may be associated with spontaneous…
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Although desmoplasia may exceptionally be encountered in banal/common and congenital nevi, the overwhelming majority of cases represent sclerosis in Spitz nevi. Desmoplastic blue neves is discussed in a separate blog. Desmoplastic nevus arising on chronic sun-damaged skin has also been described. Clinical features Desmoplastic Spitz nevus presents as a usually small, erythematous papule or nodule…
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Clinical features •In the older literature also known as juvenile melanoma, spindle & epithelioid cell nevus •First described by Sophie Spitz in 1948 •Approximately 1% of nevi in children •Most often presents in children & adolescents but may be seen the middle aged •Although cases have been documented in the elderly, I would advise extreme…
McKee Derm 