Chondroblastoma of the Occipital Bone With Atypical Genetic Markers: A Case Report

Chondroblastoma is a rare bone tumor, most often found in epiphyseal plates of long bones. It has infrequently been reported in the skull, most often in the temporal bone. We present a case of chondroblastoma of the occipital bone in a pediatric patient presenting with a bony protuberance of the occiput and imaging consistent with obstructive hydrocephalus, which persisted even after removal of the obstructing tumor. Pathological examination demonstrated that this unusually placed tumor also lacked the classic genetic markers typically associated with chondroblastoma.