MICROSCOPIC DESCRIPTION: The section shows fragments of a densely hypercellular tumour. This consists of a diffuse sheeted arrangement of markedly pleomorphic cells with large vesicular nuclei containing enlarged nucleoli and with a variable amount of pale cytoplasm. Frequent mitotic figures are identified. Tumour cells show strong nuclear immunostaining for SOX10 and strong cytoplasmic staining for tyrosinase. No staining for panctytokeratin AE1/AE3, cytokeratin CAM5.2, placental alkaline phosphatase (PLAP) or c-kit is seen in tumour cells. Numerous small lymphocytes and CD68+ monocyte-macrophages are admixed with tumour cells. The features are of metastatic malignant melanoma.
DIAGNOSIS: "?Cavernoma right postcentral gyrus": Metastatic malignant melanoma.