Findings: : Plain films reveal a large lytic lesion with a narrow zone of transition and no sclerosis about its margins in the greater trochanter. A linear region of sclerosis medially adjacent to this lesion is suggestive of a pathologic fracture. MR was obtained next and also showed a large lytic lesion with a fluid-fluid level internally. Additionally, the signal characteristics centrally were variable, consistent with blood products in various stages of degeneration. CT was next performed which clearly defines the well defined lytic lesion with pathologic fracture medially.

Diagnosis: Giant cell tumor with pathologic fracture.

Discussion: It is important to remember that the greater trochanter is an apophysis which is considered an epiphyseal equivalent for differential purposes. Given that the patient was 20 years old, the differential diagnosis of such a lesion includes: Giant cell tumor, chondroblastoma, eosinophilic granuloma and infection. The latter is less likely given the lack of any soft tissue mass.

Giant cell tumors typically present in the third and fifth decades of life. Pain is the most common presenting symptom. These lesions predominate in the long tubular bones with the femur and tibia most commonly affected. The majority of cases occur in patients who are skeletally mature with closed growth plates. In the long bones, this tumor arises in the metaphyseal region and extends to the epiphysis. However, the apophysis which is an epiphyseal equivalent is also commonly affected by this tumor.

Radiographically these lesions are characterized by an eccentric osteolytic lesion which extends to subchondral bone producing thinning and bony expansion. Margins may be well or poorly defined but periostitis and sclerosis typically are not present.

Pathologically these lesions contain multinucleated giant cells within a fibroid stroma. These giant cells may be seen in other entities such as PVNS, benign chondroblastoma, nonosteogenic fibroma, fibrous dysplasia and chondromyxoid fibroma.

In the older patient, differential considerations would include giant cell tumor, infection, malignant fibrous histiocytoma, plasmacytoma and metastases.

References:
Resnick D, et al. Diagnosis of Bone and Joint Disorders.
Second edition. W. B. Saunders, 1988.

Greenspan A. Orthopedic Radiology. Cower 1992.

Return to Musculoskeletal Teaching File Page