Exophytic giant-cell tumor of the tibial tubercle

A 23-year-old pregnant woman presented to the orthopedic tumor clinic with gradual onset of left anteriomedial tibial pain for one month and a lytic lesion of the proximal tibia on radiography. MRI showed an exophytic mass of the left tibial tubercle with fluid-fluid levels. The patient underwent surgical excision, and pathology was consistent with giant-cell tumor. This lesion is notable for its exophytic growth pattern and its location at the tibial tubercle. Giant-cell tumors are almost always epiphyseal in location in skeletally mature patients. Although the tibial tubercle is sometimes thought of as metaphyseal, it is an epiphyseal equivalent for bone tumor growth. The role of the patient's pregnancy in the pathophysiology of her tumor is unclear.