title: Malignant melanoma originating from intradermal nevi. A clinicopathologic entity.
abstract: Two cases of malignant melanoma arising in preexisting intradermal nevi without a junctional element are described. These cases and the two known to have been reported previously demonstrate similar clinical and morphologic findings. These include an innocuous gross appearance, a nodular growth pattern, and deep levels of invasion. It appears that the origin of the tumor in the dermis conceals malignant transformation. The consequent time lapse and the dermal position of the lesion favor deep penetration of the tumor prior to removal.
mesh_terms: D000328:Adult; D002471:Cell Transformation, Neoplastic; D005260:Female; D006801:Humans; D008297:Male; D008544:Melanocytes / Q000473:pathology; D008545:Melanoma / Q000473:pathology*; D008875:Middle Aged; D009378:Neoplasms, Multiple Primary / Q000473:pathology*; D009508:Nevus, Pigmented / Q000473:pathology*; D012867:Skin / Q000473:pathology; D012878:Skin Neoplasms / Q000473:pathology*