Background: Giant cell tumor of bone accounts for 4% to 5% of
primary bone tumors. Approximately 1% of cases present as multiple synchronous
or metachronous lesions. In this study, we describe the clinicopathologic
features of thirty cases of multicentric giant cell tumor.
Methods: Thirty patients who had two or more separate lesions that
had been pathologically confirmed to be giant cell tumors were identified.
Radiographs were reviewed to evaluate the characteristics and locations of the
tumors. Histologic reexamination was performed to document morphologic
features. Clinical information and follow-up data were obtained from the
Results: The male:female ratio was 1:2, with an average age at
presentation of twenty-one years. Fifty-nine percent of the patients were
younger than twenty years of age. There were ninety-four tumors in the series,
with an average of three (range, two to nine) per patient. Most tumors had
arisen in the long bones. Six patients had synchronous ipsilateral involvement
of the distal part of the femur and the proximal part of the tibia.
Radiographically, the tumors in long bones manifested as expansive lytic
lesions involving the metaphysis and extending into the epiphysis. A minority
of the tumors were confined to the metaphysis, had features of a fibro-osseous
or bone-forming lesion, or arose in skeletally immature patients. Secondary
histopathologic changes including fibrohistiocytic regions, reactive bone
formation, or aneurysmal bone cyst-like changes were not uncommon. Most tumors
were treated with curettage (64%) or resection (22%). The recurrence rate was
similar to that of solitary giant cell tumors. Metastatic disease developed in
three patients, and two patients had malignant transformation.
Conclusions: Multicentric giant cell tumors occur more often in
younger patients than do solitary giant cell tumors, and they frequently
present as synchronous lesions around the knee. Some tumors appear as
bone-forming or fibroosseous tumors on imaging studies as a result of
fibrohistiocytic regions and reactive bone formation. The risk of recurrence
depends on the type of surgery that is performed.
Level of Evidence: Therapeutic Level IV. See Instructions
to Authors for a complete description of levels of evidence.