A case of recurrent giant cell tumor of bone with malignant transformation and benign pulmonary metastases

Abstract

Giant cell tumor (GCT) of bone is a locally destructive tumor that occurs predominantly in long bones of post-pubertal adolescents and young adults, where it occurs in the epiphysis. The majority are treated by aggressive curettage or resection. Vascular invasion outside the boundary of the tumor can be seen. Metastasis, with identical morphology to the primary tumor, occurs in a few percent of cases, usually to the lung. On occasion GCTs of bone undergo frank malignant transformation to undifferentiated sarcomas. Here we report a case of GCT of bone that at the time of recurrence was found to have undergone malignant transformation. Concurrent metastases were found in the lung, but these were non-transformed GCT.

Metastatic Giant Cell Tumor of Bone: A Case Report

“…Lungs are the main metastatic site, and the recurrence of bone disease increases the risk of distant implants; approximately 5% of these recurrent cases develop lung disease [4,9,10]. Multicenter disease at the diagnosis, as described above, is a very rare condition, affecting less than 1% of the patients [2].…”

“…It is assumed that giant cells are monocytes transformed into osteoclasts that express RANKL (kappa B nuclear factor receptor), an essential growth factor in the osteoclastic differentiation and activation [4,5,10,12].…”

“…Radiotherapy presents a local control rate of the disease of 60-84%; however, due to the risk of sarcomatous degeneration, described in up to 11% in some series of cases, this treatment modality is reserved for cases with lesions unable to be removed with surgical margins, like those located in sacrum [4,5,8,10,12,15].…”

Giant cell tumor of bone: current review of morphological, clinical, radiological, and therapeutic characteristics

“…Primary malignant GCTB is the rarest (about 1-3 % of all cases of GCTB) and has cells characteristic of a sarcomatous process located in areas of typical benign GCTB [7,32,43]. Secondary malignant GCTB is present in 5-10 % of cases and is described as a metachronous highly differentiated sarcoma that is superimposed on a primary histologically benign GCTB after surgery or radiotherapy [7,9,32,43]. The clinical features of primary and secondary malignant GCTBs are similar to those of a benign lesion; the primary is virtually indistinguishable by radiography while the secondary has a much more malignant radiographic appearance but sometimes it too is indistinguishable from a benign lesion [43].…”

“…It accounts for about 5% of all primary bone tumors in adults and predominantly occurs in the third and fourth decade of life with a slight predilection for females [2,7,8]. GCTB is described as a locally invasive tumor that arises close to a joint in a mature bone [2,9]. It usually affects the meta-epiphyseal region of long bones, preferably the bones around the knee joint, the distal radius, and the proximal humerus [1][2][3][4]10].…”