Radiology Quiz Case 2: Diagnosis

Giant cell tumor is a rare primary bone neoplasm that arises from nonosteogenic stromal cells of the bone marrow. It tends to occur in the ends of long bones. Skull involvement is extremely rare, accounting for only 2% of all GCTs.¹ The most common locations in the skull are the sphenoidal, temporal, and ethmoidal bones, because GCTs occur in bones that develop by endochondral rather than membranous ossification.¹ The tumor most commonly presents in the third and fourth decades of life and has a slight female predominance.²