Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0268596 (EMA)
 2,520 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Nevus cell components have been observed in up to 40% of melanomas, but little is known of the pathobiology of these components in relation to their malignant potential. We studied 44 nevi of the typical, dysplastic, congenital, and Spitz types with a battery of monoclonal and polyclonal antibodies that react on formalin-fixed, paraffin-embedded tissues (HMB.45, S-100 protein, RAP-5, epithelial membrane antigen [EMA], and neuron-specific enolase [NSE]) by avidin-biotin immunohistochemical methods. EMA and RAP-5 (which detects the ras oncogene-associated P21 protein) were negative in all cases. Melanoma-specific HMB.45 was strongly reactive with the epidermal component and had a weak to negative reaction with the dermal component in the typical nevi. However, the reaction seen with HMB.45 in the junctional component of dysplastic nevi, congenital nevi, and some Spitz nevi was heterogeneous. One Spitz nevi showed HMB.45 staining in a pattern near to that of melanoma. In contrast to HMB.45, S-100 protein labeled nevomelanocytes, regardless of whether they were within the epidermis or dermis, although, in half of the dysplastic nevi, the reaction was heterogeneous, with some atypical cells failing to stain. But, with cytologically atypical junctional component (dysplastic-appearing), congenital nevi also stained heterogeneously for S-100 protein compared with the dermal component. NSE stained the central component of some Spitz nevi more intensely than the lateral component. Junctional nevomelanocytic subsets of some congenital nevi revealed HMB.45 and S-100 reactivity similar to dysplastic nevi.
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PMID:Typical, dysplastic, congenital, and Spitz nevi: a comparative immunohistochemical study. 229 3

We present two cases of melanoma arising in a dysplastic nevus that contained intradermal sebocyte-like melanocytes characterized by a scalloped dark-staining nucleus surrounded by the pale multivacuolated cytoplasm imitating sebaceous differentiation. Both patients were women, aged 49 and 55 years. Location included the back and temporal area. Microscopically, both cases had the following features in common: the melanoma in situ, which was of the superficially spreading type, was associated with a dysplastic compound nevus, in which the sebocyte-like cells were identified in the intradermal nevus part of the lesion. The sebocyte-like cells comprised a minor component but were immediately recognizable and appeared as cells with multivacuolated neoplasm and scalloped nuclei arranged in nests. Some contained melanin in the cytoplasm. They stained positively for S-100 protein and melan A but were EMA and HMB-45 negative. The conventional part of the nevi demonstrated the same phenotype, with the exception of the melanocytic nests located at the dermoepidermal junction that were HMB-45 positive. The cases are discussed in the context of the pertinent literature.
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PMID:Melanoma associated with a dysplastic nevus: report of two cases with unusual sebocyte-like melanocytes in the nevus part of the lesion. 1803 54