Pediatric synchronous multifocal and disseminated cerebrospinal classic medulloblastoma revealed by bilateral decreased visual acuity: a case report.

Medulloblastoma (MB) is a rapidly growing malignant solid tumor that arises from stem cells located in the subependymal germinal matrix or outer granular layer of the cerebellum. It represents 15 to 30% of pediatric brain tumors and less than 1% of primary brain tumors. The reason for the high incidence of MB in children compared to adults is the embryonic origin of the tumor. In typical cases, MB manifests as a solitary lesion in the fourth ventricle or in the cerebellar parenchyma; cases of synchronous multifocal and disseminated MB are quite rare in patients without familial tumor syndromes. To date, only 7 cases in adults and a single pediatric case with Gorlin syndrome have been described previously. Here, the authors report a new case of synchronous multifocal classic cerebrospinal histologically confirmed MB in a 10-year-old male patient revealed by bilateral decreased visual acuity without any other localizing neurological signs. The authors will proceed with a review of the current literature regarding this rare entity.