Giant cell tumor in Paget's disease of bone: familial and geographic clustering.

Four patients with benign giant cell tumor and one patient with probable benign giant cell tumor associated with Paget's disease of bone are reported. The familial and geographic clustering of these cases is unique in that three patients were related and all patients traced ancestral roots to the same area of southern Italy. Tumors arose from the cranial or facial bones in three patients and from vertebral bodies in two patients. All caused symptoms by local compression, and treatment by curettage or radiotherapy was successful in all patients. Three separate tumors in one patient shrank dramatically in response to treatment with high doses of dexamethasone, and one patient whose tumor caused spinal cord compression showed marked improvement in neurologic function on therapy with dexamathasone.