Fibrosarcoma Development 15 Years After Curettage and Bone Grafting of Giant Cell Tumor of Bone

Abstract

Malignant transformation of conventional giant cell tumor of bone is rare and usually occurs with irradiation. This article describes a case of malignant transformation of a giant cell tumor 15 years after initial curettage and bone graft. A 35-year-old man was admitted to the hospital with a recurrent giant cell tumor of the distal femur. On presentation, the patient reported the insidious onset of a dull aching pain in the distal part of the left thigh 4 months prior to admission. Radiographs revealed a destructive lesion in the left distal femur. Needle biopsy revealed recurrence of giant cell tumor with suspected malignant transformation. The patient underwent en bloc resection of the distal femur with adequately wide margins and reconstruction of the knee joint with a prosthesis. Pathological findings showed malignant transformation of a giant cell tumor to high-grade spindle cell sarcoma. Immunohistochemistry showed diffuse and strong p53 expression. A diagnosis of secondary fibrosarcoma was made after discussion. Unfortunately, the tumor proved to be highly resistant to the chemotherapy, and the patient died of multiple lung metastases 14 months after the diagnosis of malignant transformation. What has to be stressed in this case is that any late recurrence must be approached considering the possibility of a secondary induced primary tumor. Because of the rarity of this disease, the effective therapeutic strategy for fibrosarcoma secondary to giant cell tumor is lacking. In addition, identification of the p53 mutation may help in diagnosing cases of potential malignant transformation of giant cell tumor.

A High-grade Sarcoma Arising in a Patient With Recurrent Benign Giant Cell Tumor of the Proximal Tibia While Receiving Treatment With Denosumab

“…However with an incidence ranging from 1.4% to 6.6%, most cases follow radiation therapy or multiple local recurrences [1,3,9,12,18]. In histologically typical giant cell tumor of bone, without former radiotherapy, sarcomatous change has been reported in less than 1% of patients [24].…”

Histological Regression of Giant Cell Tumor of Bone Following RANK Ligand Inhibition

“…Cases of malignant transformation of GCTBs, specifically sarcomatous transformation, have been reported. 5 , 6 The average rate of malignant transformation is very low; higher incidences of malignant transformation have been reported with previous irradiation of the involved site where the primary giant tumor arose. 7 A clear understanding of the steps leading to spread and malignant transformation of GCTBs is lacking.…”

“… 7 A clear understanding of the steps leading to spread and malignant transformation of GCTBs is lacking. Secondary genetic events, including changes in p53 status 3 , 5 , 8 and amplification of c-myc, 9 have been implicated. C-myc status further seems to correlate with development of pulmonary metastases.…”

Clinical Case: Treatment of a Giant Cells Tumor of the Proximal Femur in a Disadvantaged Area

“…Whatever the method used, recurrences are frequent, occurring between a few months and five years, in proportions of 20% to 40% according to the series [16] [17] [18] [19]. In 15% of cases, it is malignant degeneration [20] [21] [22]. The recurrence factors explored in the literature are age, sex, tumor site, histological grade, pathological fracture and type of surgery.…”

“…This seems to testify to the efficacy of Denosumab, even if administered for a limited time. However, regular monitoring should be continued for a few more years because recurrences at fifteen or even twenty years have been described [20] [30].…”