Six pediatric patients with cerebellar hemangioblastoma were screened for germline or somatic mutations of the von Hippel-Landau gene, in a study at Stanford University Medical Center, Palo Alto, CA. Two testing positive for mutations had a history of clinical manifestations of von Hippel-Lindau disease, whereas 4 testing negative had solitary hemangioblastoma and no history of the disease. These solitary cases may involve a molecular process unrelated to the von Hippel-Lindau tumor suppressor pathway. 
COMMENT. Hemangioblastoma is a rare intracranial tumor, accounting for less than 0.5% of all pediatric brain tumors (Ries et al, 2001). The apparent absence of von Hippel-Lindau (VHL) gene abnormalities in childhood sporadic cerebellar hemangioblastoma indicates an alternative mechanism of tumorigenesis from that in adults. In 3 reports including 50 adult cases of sporadic cerebellar hemangioblastoma cited by the authors, about 50% of patients screened had somatic VHL gene mutations. VHL disease is familial with dominant inheritance and manifested by malignant and benign neoplasms of eyes, kidneys, adrenal glands, spine, and brain. The VHL gene is a tumor suppressor gene located on chromosome 3p25-26.