Giant cell tumor of soft tissue: A case report

INTRODUCTION AND IMPORTANCE: Giant cell tumor of soft tissue (GCT-ST) is a rare primary neoplasm of soft tissues. It usually involves superficial and deeper soft tissues of upper and lower extremities, followed by trunk. CASE PRESENTATION: A 28-year-old female, presented with a painful mass in left abdominal wall for three months. On examination, it measured 4 × 4 cm with ill-defined margins. CECT showed ill-defined enhancing lesion deep to muscle planes with possible invasion of peritoneal layer. Histopathology showed multinodular architecture with intervening fibrous septa and metaplastic bony tissue encasing the tumor. Tumor composed of round to oval mononuclear cells and osteoclast like multinucleated giant cells. Mitotic figures were eight per hpf. A diagnosis GCT-ST of anterior abdominal wall was made. Patient was treated with surgery followed by adjuvant radiotherapy. Patient is disease free at one year follow up. CLINICAL DISCUSSION: These tumors mostly involve extremities and trunk and usually presents as a painless mass. Clinical features depend upon the exact location of the tumor. Common differential diagnosis includes tenosynovial giant cell tumors and malignant giant cell tumors of soft tissue and GCT of Bone. CONCLUSION: Diagnosis of GCT-ST is difficult on cytopathology and radiology alone. Histopathological diagnosis should be done to rule out the malignant lesions. Complete surgical resection with clear resection margins is the mainstay of treatment. Adjuvant radiotherapy should be considered in case of incomplete resection. Long follow-up is necessary for these tumors as local recurrence and risk of metastasis cannot be predicted.