Bone Imaging in “Giant” Giant Cell Tumor

A 54-year-old man was found to have a giant cell tumor of the right femur 30 years ago. The tumor was treated by excision and radiotherapy. Local and iliac involvement occurred later and the disease remained static after chemotherapy. 3-phase Tc-99m bone scintigraphy, done for possible recurrence in a small right-thigh mass, showed a huge mass in the right iliac and right femoral region. The tumor showed mild hypervascularity, and faint bone tracer uptake in the parenchyma. CT showed a mostly isodense lesion with mild contrast enhancement. Histology confirmed the diagnosis of giant cell tumor and there was no malignant transformation. This is a “giant” giant cell tumor.