Extracranial Medulloblastoma With Myogenic Differentiation: Report of a Rare Event

Medulloblastoma accounts for nearly 10% of childhood primary central nervous system (CNS) malignancies. However, it is rare in adults. Extracranial metastasis is commonly documented to involve bones but rarely involves lymph nodes. Herein, we present an unusual case of primary CNS medulloblastoma in an adult patient with extracranial metastasis to a lymph node, which exhibits a myogenic differentiation. To the best of our knowledge, this is the fourth reported case of medulloblastoma in an adult with extracranial metastasis to the lymph node and the first reported case of extracranial metastatic medulloblastoma with myogenic differentiation that involves a lymph node.