Lipomatous medulloblastoma: a rare adult tumor variant with a uniquely favorable prognosis.

BACKGROUND

Lipomatous medulloblastoma is a rare but apparently distinct variant of medulloblastoma. There have been only 14 prior published cases. We report an additional case of an adult who presented with a multicentric form of this unique lesion.

METHODS

A 45-year-old woman underwent magnetic resonance imaging for evaluation of progressive headaches, nausea/vomiting, vertigo, and ataxia. Multiple bilateral mass lesions in the posterior fossa were noted, along with obstructive hydrocephalus and significant mass effect.

RESULTS

Via a right suboccipital and retrosigmoid craniotomy the largest cerebellar lesion was resected and a second lesion biopsied. The third mass on the contralateral side was not disturbed. Postoperatively the patient received fractionated radiotherapy to a dose of 54 Gy and chemotherapy with cisplatin, PCNU, and vincristine for 1 year. She is alive without deficit, with a Karnofsky Performance Status of 100, and with no evidence of disease on neuroimaging 3 years after diagnosis.

CONCLUSIONS

This distinct variant of medulloblastoma appears to occur in adults only and has a uniquely favorable prognosis, even with incomplete resection with institution of appropriate adjuvant therapies. Multicentricity does not imply a less favorable prognosis.