Visualization by dynamic and static osseous scintigraphy of pelvic chondrosarcoma in multiple hereditary exostosis

Malignant degeneration to chondrosarcoma occurred in the left hemipelvis of a patient with multiple hereditary exostosis. Tc-99m HDP bone scintigraphy revealed markedly increased focal uptake in the areas of left superior pubic ramus, obturator foramen, and ischium with displacement of the urinary bladder. Of particular interest was the presence of vascularities seen in the flow and blood pool scintigrams. Following surgical exeresis, the gross appearance and histologic features of the tumor were identified as those of a low grade chondrosarcoma.