Surgical giant cell tumour of the distal ulna managed by en bloc resection, ipsilateral fibular grafting and distal radioulnar ligament reconstruction using palmaris longus tendon: a rare case report

Giant cell tumour of bone is a benign but locally aggressive skeletal tumour, most commonly involving the epimetaphyseal region of long bones around the knee. Involvement of the distal ulna is rare and poses a reconstructive challenge because of its relationship with the distal radioulnar joint, triangular fibrocartilage complex, ulnocarpal articulation, and surrounding tendons. We report a case of a 25 year old female who presented with a gradually progressive swelling over the right wrist for six months. Clinical examination revealed a large globular swelling over the distal ulna with painful restriction of wrist motion and intact distal neurovascular status. Radiographs showed a large expansile multiloculated lytic lesion involving the distal ulna with cortical breach. MRI demonstrated a 7.8×8.4×9.6 cm expansile heterogeneous lesion involving the epimetadiaphyseal region of the distal ulna, with extensive cortical destruction, articular extension, and displacement/encasement of adjacent tendons. Fine needle aspiration cytology showed mononuclear stromal cells with numerous osteoclast-like multinucleated giant cells, suggestive of giant cell tumour. The patient underwent en bloc resection of the distal ulna with a 2 cm healthy bony margin, followed by reconstruction using a 12 cm ipsilateral fibular graft. Distal radioulnar joint stabilization was performed using palmaris longus tendon graft based on the Adams–Berger anatomical reconstruction principle, and fixation was reinforced with Kirschner wires and a dynamic compression plate. Early follow-up at one and three months showed satisfactory wound healing, maintained limb alignment, and useful active limb positioning. This case highlights that aggressive distal ulna giant cell tumour can be managed by wide resection with fibular graft reconstruction and soft-tissue stabilization, aiming to achieve local tumour control while preserving wrist and forearm function.