&NA;A 39‐year‐old man developed persistent bleeding into the ventricular system after having undergone needle biopsy of what was presumed to be a left frontal neoplasm. He subsequently developed obstructive hydrocephalus that required shunting and died in a semivegetative state some 5½ months later. At autopsy, although no neoplasm was identified at the operative site, there was massive collagen deposition within the ventricular system that extended into the spinal subarachnoid compartment. Although we have been able to find only three cases in the literature with detailed descriptions of similar pathological findings, we believe that our observations emphasize the potential for a complication of intraventricular and subarachnoid hemorrhage that is not widely recognized. (Neurosurgery24:771‐775, 1989)