Primary giant cell tumour of the patella: A rare entity a case report with five-year follow-up

Abstract

Background: Giant cell tumor of bone is a benign but locally aggressive tumor that most commonly involves the epiphyseal region of long bones. Involvement of the patella is exceptionally rare and often poses diagnostic and therapeutic challenges due to its uncommon location and nonspecific clinical presentation. Case Presentation: We report the case of a twenty-five-year-old female who presented with intermittent anterior knee pain for two years, with recent worsening over two months. Clinical examination revealed localized swelling and tenderness over the patella. Radiographs demonstrated an expansile lytic lesion of the patella with a soap-bubble appearance, while magnetic resonance imaging showed diffuse patellar involvement with cortical breach and adjacent soft tissue extension. A diagnosis of giant cell tumour of the patella was made based on radiological and histopathological findings. Management and Outcome: The patient was managed with patella-preserving surgery using extended intralesional curettage. Although bone cement reconstruction was initially attempted, adequate containment could not be achieved, and reconstruction was successfully performed using autologous iliac crest bone graft. Histopathological examination confirmed the diagnosis of giant cell tumor of bone. At five-year follow-up, the patient remained pain free with good graft incorporation, preservation of the patella, satisfactory knee range of motion, and no evidence of local recurrence. Conclusion: Giant cell tumor of the patella is a rare condition that requires a high index of suspicion for early diagnosis. Patella-preserving surgery with meticulous curettage and appropriate reconstruction can provide excellent oncological control while maintaining knee function. Long-term follow-up is essential to monitor for recurrence and functional outcome.