Familial medulloblastoma.

Medulloblastomas account for 20% of all primary brain tumors. The vast majority of them are sporadic. Familial medulloblastoma is very rare--only a few cases have been reported worldwide. Most were observed in siblings of the same sex. The affected children presented at various ages and all of them have died, usually within the first 2 years following diagnosis. The authors describe a case of familial medulloblastoma with unusual characteristics: Two siblings of different sex and a second-degree relative have presented at exactly the same age of 18 months. The histologic pattern was the same in all patients, that of desmoplastic medulloblastoma. All patients are alive and remain in remission 12, 5, and 11 years, respectively, after diagnosis. The genetics and the pathogenesis of the disease remain obscure.