A Case of Malignant Melanoma Arising in Mediastinal Malignant Teratoma

Figure 4

Cranial bone biopsy: black lesions are observed macroscopically at the surface and in the lumen of specimen. Histologically, metastasis of large heterozygous malignant cells is observed in the medullary cavity. Tumor cells are round or polygonal, including multinucleated cells with clear nucleoli, which have melanin granules in a wide cytoplasm. The histology is consistent with malignant melanoma. Large heteromorphic cells containing melanin were found with mesenchymal spindle-shaped cells of primary immature mediastinum teratoma.

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