Secondary Malignant Transformation of Giant Cell Tumor of Bone: Is It a Fate?

Malignant giant cell tumour of distal ulna

Giant cell tumour (GCT) accounts for 5% of all primary bone tumours. GCT in the distal third of ulna is quite rare. We present a case of recurrent GCT in distal third of ulna with malignant features involving tenosynovium. The case was treated by wide resection of tumour and on follow up, patient recovered well with no evidence of further recurrence. Considering the features, according to the literature reviewed, is the first case of its type.

Osteosarcoma of the Distal Femur Presenting as Giant Cell Tumor: A Case Report

The most frequent benign bone tumor, known as a giant cell tumor (GCT), typically develops in the second and third decades of life. GCTs of the bone that have already been diagnosed and have already undergone treatment with denosumab therapy, curettage or excision, or radiotherapy frequently develop malignant transformation. A very uncommon occurrence involves a GCT of the bone that has always been malignant. Here, we describe the case of a 25-year-old man with a large cell tumor of the distal femur discovered after six months of symptom onset. The MRI suggested an aneurysmal bone cyst or subsequent modifications of an aneurysmal bone cyst in a GCT. A biopsy was performed, and the results pointed to a benign GCT of the bone. There were no pleomorphic or hyperchromatic lesions, unusual mitoses, or cellular atypia. The patient was treated with tumor removal and internal fixation using plate osteosynthesis two weeks later. The samples were sent for histopathology. The report was suggestive of osteogenic sarcoma or malignant transformation of the giant cell. This could happen due to the possibility of a biopsy sample being taken from an area not representative of the tumor site, which is not uncommon since the osteosarcoma also contains areas of conventional GCT. Thus, osteosarcoma usually mimics conventional GCT of the bone.

Giant Cell Tumor of Talus - A Case Report

Introduction

A giant cell tumor (GCT) is a benign tumor of bones which commonly arises from epiphysis of long bones. The tumor is locally aggressive and rarely metastasizes to the lungs. GCT of small bones of the foot and ankle is very rare. The GCT of the talus is very rare, and only a few case reports and series are described in the literature. In general, the GCT is monostotic, and few incidences of multicentricity have been described in the foot and ankle bones literature. Here are the findings of our case GCT of talus and reviews of earlier literature.

Case Report

We present a case of a GCT of the talus in a 22-year-old female. Patient presented with pain in ankle with mild swelling and tenderness at ankle. Radiograph and Computer tomography scan conformed an eccentric osteolytic lesion on anterolateral part of talus body. Magnetic resonance imaging showed no extra osseous extension or articular surface breach. Biopsy conformed the lesion to be giant cell tumor. The tumor was reated with curettage and bone cement filling.

Conclusion

Giant cell tumor of talus is extremely rare and presentation of these tumor may change. Curettage and bone cementing are an effective method of treatment. It gives early weight bearing and rehabilitation.

A Retrospective Audit of Demography and Different Surgical Modalities Adopted for Giant Cell Tumor of Bone in Eastern India

Background and objective

There is scarce data on demography and different surgical treatment modalities for giant cell tumor of bone (GCTB) from eastern India. In light of this, the present study aimed to examine the demographic characteristics, different surgical treatment modalities, and recurrence rate of GCTB at a tertiary care institute in Bihar.

Materials and methods

A retrospective audit of 52 GCTB patients who were treated at the center from January 2016 to December 2020 was conducted. The minimum follow-up period was one year. GCTB patients underwent surgical procedures ranging from extended intralesional curettage with bone graft or bone cement with or without fixation to wide local excision to resection with or without reconstruction or amputation depending on the stage and site of the tumors.

Results

The mean age of patients was 31.86 years (range: 13-67 years). The distal femur (20 patients, 38.46%) and proximal tibia (11 patients, 21.15%) were the most common sites of the tumor. Sixty-eight confirmed cases (male: 32, female: 36) of GCTB were operated on, with a male-to-female ratio of 1:1.125. Sixteen patients (four males and 12 females) were lost to follow-up. So, the final study consisted of 52 patients with a median age of 28 years (first quartile: 24 years, third quartile: 38 years). The majority of patients (32 patients, 61.53%) were in the third and fourth decades of life.

Conclusion

Based on this retrospective audit, it is concluded that the knee region is the most common site of GCTB. Surgery is the mainstay of management. Most of the patients came under Campanacci Grade 3 with low compliance with follow-up and adherence to the treatment. Hence, educational programs, the establishment of early detection centers, and timely referral to expert treatment are necessary.

Clinicopathological and histological analysis of secondary malignant giant cell tumors of bone without radiotherapy

Giant cell tumor of bone (GCTB) is an intermediate bone tumor that rarely undergoes malignant transformation. Secondary malignant GCTB (SMGCTB) is defined as a lesion in which high-grade sarcoma occurs at the site of previously treated GCTB. The present study retrospectively reviewed the medical records of patients with GCTB treated at Okayama University Hospital between April 1986 and April 2020. The clinicopathological and histological features of patients with SMGCTB without prior radiotherapy were investigated. A total of three patients (4%) with SMGCTB were detected, and the tumor sites were the distal ulna, distal femur and sacrum. Two of the patients had been treated with curettage and bone graft, and one had been treated with denosumab. In all cases, the lesions were made up of two components, the conventional GCTB component and the malignant component. The Ki67 labeling index was higher in the malignant components of SMGCTB and metastatic lesions compared with that in primary and recurrent conventional GCTB, or the conventional GCTB component of SMGCTB. Moreover, p53 expression was higher in these same components in patients who underwent curettage and bone grafting; however, there was no difference in the patient that received denosumab treatment. In this patient, clinical cancer genomic profiling revealed loss of CDKN2A, CDKN2B and MTAP expression. All three patients developed distant metastasis. The patients with SMGCTB in the ulna and femur died 13 and 54 months after detection of malignant transformation, respectively. The patient with SMGCTB in the sacrum received carbon-ion radiotherapy to the sacrum and pazopanib; the treatment was effective and the patient was alive at the last follow-up 3 years later. In conclusion, p53 may be associated with malignant transformation in GCTB. Future studies should investigate the association of between denosumab treatment and malignant transformation, as well as molecular targeted therapy to improve the clinical outcomes of SMGCTB.