title: Dermatopathologic variants of malignant melanoma.
abstract: An appropriate biopsy is the pivotal procedure that facilitates accurate histopathologic diagnosis of a pigmented skin lesion. Excisional skin biopsy is the method of choice for removing a suspected malignant melanoma. More than 95% of malignant melanomas that involve the skin belong to one of the four most common clinicopathologic categories: superficial spreading, nodular, lentigo maligna, and acral lentiginous melanoma. A small but important group of cutaneous melanomas can be classified as unusual variants. Many of these unusual variants have a distinct histopathologic appearance; they include desmoplastic melanoma, neurotropic melanoma, pedunculated melanoma, metastatic melanoma, amelanotic melanoma, melanoma arising within a benign nevus, regressing ("invisible") melanoma, and balloon cell melanoma. Other lesions may simulate malignant melanoma histopathologically. Immunohistochemical stains, such as S-100 protein, vimentin, keratin, and HMB-45, are useful for distinguishing these lesions from true melanoma.
authors.affiliation: Department of Dermatology, Mayo Clinic Jacksonville, Florida 32224, USA.
authors.forename: C
authors.initials: C
authors.lastname: Perniciaro
mesh_terms: D001706:Biopsy / Q000379:methods; D003937:Diagnosis, Differential; D006801:Humans; D007150:Immunohistochemistry; D008545:Melanoma / Q000473:pathology*; D012878:Skin Neoplasms / Q000473:pathology*