Infratentorial stereotactic biopsy. A review of 11 cases.

A review of the stereotactic cases performed at the University of Iowa between February, 1985, and December, 1990, yielded 12 infratentorial stereotactic biopsies in 11 patients. A definitive diagnosis was obtained in 9 of 11 patients. One patient required a second biopsy to obtain a diagnosis and 1 yielded cystic fluid only. The pathological diagnosis obtained included 4 high-grade gliomas, 2 undifferentiated adenocarcinomas, 2 low-grade astrocytomas, 1 malignant ependymoma, 1 pontine hematoma and 1 cyst. None of the patients experienced increased neurological deficit following biopsy and there was no mortality. One patient developed postoperative meningitis. We conclude that stereotactic biopsy of infratentorial lesions can be performed safely with a high probability of obtaining a diagnosis. Adequate tissue diagnosis is necessary to direct further therapy.