Myogenic and melanotic differentiated medulloblastoma: case report.

Medulloblastoma is the most common malignant tumor of childhood and usually arises from the cerebellar vermis. Several histological types of medulloblastoma have been described. Myogenic and melanotic differentiated medulloblastoma are seldom seen. We present a case diagnosed as myogenic medulloblastoma with focal areas of melanotic differentiation. A 4-year-old boy was admitted due to headache, nausea and vomiting for a month. MRI revealed a heterogeneous enhanced posterior fossa tumor rising from the fourth ventricle. He was operated and pathological examination of the specimen revealed myogenic medulloblastoma with myogenic and melanotic differentiation. According to our knowledge there are six cases reported in the literature so far. Oncogenic factors in medulloblastoma development are controversial. Presence of multiple differentiation patterns supports a pluripotent origin for these tumors.