Patellar Tendon Fibroma Mimicking Hemangioma: A Report on a Rare Case.

Fibroma of the tendon sheath (FTS) is an uncommon benign soft tissue tumor of the tendon sheath. Clinical and radiological features are not distinctive enough to clinch the diagnosis preoperatively. FTS occurs mostly around small joints such as the fingers, hands, and wrist. However, it rarely arises around a large joint (knee, shoulder, elbow, or ankle). This case report describes a rare presentation of fibroma within the patellar tendon. The patient, a 35-year-old male, presented with progressive pain and swelling in his left knee. Clinical examination, imaging studies, and histopathological analysis mimicked hemangioma but confirmed the diagnosis of a patellar tendon fibroma. A surgical excision was performed, leading to significant improvement in symptoms and functional recovery. This case highlights the importance of considering rare soft tissue pathologies in the differential diagnosis of knee joint disorders.