title: Malignant melanoma in the CNS, subtyping and immunocytochemistry.
abstract: Paraffin-embedded specimens from 21 patients (mean age 49 years) with malignant melanocytic tumors of the central nervous system were studied. Extraneuronal primary tumors were situated at the trunk (38%), the lower (14%) or upper extremity (10%), and the head/neck region (5%). In 33% no extraneural primary tumor could be detected. The tumor location was frontal (19%), occipital (19%), parietal, spinal, multifocally (14%, respectively), or temporal (5%). Four subtypes were distinguished according to the predominant histological cell type: pleomorphic, epithelioid, spindle- and mixed-cell tumors. 29% contained no melanin, most of them belonging to the epithelioid subtype. The morphology and immunohistochemical reactivity for different antibodies (KL-1, EMA, VIM, HMB-45, NKI-C3, S-100, and MIB-1/Ki-67) were assessed. Positive staining was demonstrated for HMB-45 (in 86% of cases), NKI-C3 (100%), S-100 (95%), vimentin (75%), and KL-1 (33%). No expression of the cytokeratin EMA could be detected. The mean proliferation index measured by MIB-1 immunoreactivity was 21%. The 4 histological subtypes were found to express different antigen patterns. In the analysis of CNS tumors of unknown origin, the panel of antibodies used for diagnosis should include HMB-45 as the most specific marker for malignant melanoma.
authors.affiliation: Neurologisches Institut (Edinger Institut), Universitätskliniken Frankfurt, am Main, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Bär
authors.forename: W
authors.initials: W
authors.lastname: Schlote
mesh_terms: D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor; D001932:Brain Neoplasms / Q000737:chemistry / Q000473:pathology*; D002455:Cell Division / Q000276:immunology; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D019394:Ki-67 Antigen / Q000032:analysis; D008297:Male; D008545:Melanoma / Q000737:chemistry / Q000473:pathology*; D008875:Middle Aged; D016612:Paraffin Embedding
chemical_list: D014408:Biomarkers, Tumor; D019394:Ki-67 Antigen