Malignant Giant Cell Tumor of the Tendon Sheath in the Hand-A Case Report

Abstract

Giant cell tumors of the tendon sheath (GCTTS) are usually benign, although they tend to recur after excision. Malignant giant cell tumors (GCTs) are even rarer, with the prognosis being very poor. GCTTS is a benign synovial proliferative disorder of unknown origin. GCTTS usually present as a slowly growing mass without any adverse symptoms. Although tumors of the hand are relatively rare, GCTTS most commonly occur in this area (especially on the fingers and usually adjacent to joints), second only to simple ganglion cysts. Lesions can include benign GCTs coexisting with malignant GCTs. It must be emphasized that malignant soft tissue tumors of the hand (excluding the skin) are exceptionally rare. We report on an extremely rare case concerning a malignant GCTTS and its specific localization to the right hand. A patient with a clinical history of four benign GCTs reported to our hospital for the first time with what was initially considered another benign tumor, in the little finger of the right hand. Physical examination revealed rigid, swelling indurations and flexion contracture deformity of that finger. A chest X-ray showed previous TB lesions. Results from the laboratory examination, including blood serum, were normal. Tissue analysis led to the discovery of microscopic features identical to those found in malignant GCTTS. Forearm amputation was therefore performed for complete removal of the tumor. Local recurrence is a risk factor for pulmonary metastasis, but the CT-guided biopsy revealed no malignancy in the lung. The patient is currently well with no recurrence or metastases seven years after the excision operation.