Melanotic schwannoma coexpression of vimentin and glial fibrillary acidic protein.
A 35-year-old man was operated for a thoracic wall tumor which bulged into the pleural cavity. Histologic examination showed a spindle cell tumor with numerous psammoma bodies and a heavy melanin pigmentation. Electron microscopy revealed melanosomes and a continuous basal lamina surrounding all tumor cells, compatible with the diagnosis of a melanotic schwannoma. The tumor cells were S-100 protein-positive, and there was an abundant pericellular laminin-positivity. Practically all tumor cells were vimentin-positive, while cytokeratin, desmin and neurofilaments were absent. Glial fibrillary acidic protein was found in single tumor cells, suggesting the presence of focal glial differentiation in melanotic schwannoma.
D000328:Adult; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism*; D006651:Histocytochemistry; D006801:Humans; D007120:Immunochemistry; D008297:Male; D008854:Microscopy, Electron; D009442:Neurilemmoma / Q000378:metabolism* / Q000473:pathology / Q000648:ultrastructure; D013899:Thoracic Neoplasms / Q000378:metabolism* / Q000473:pathology / Q000648:ultrastructure; D014746:Vimentin / Q000378:metabolism*
D005904:Glial Fibrillary Acidic Protein; D014746:Vimentin