Incidental diagnosis of bilateral synovial lipomatosis in long standing knee osteoarthritis

Abstract

BackgroundSynovial lipomatosis is a rare, benign lipoma like intra-articular lesion commonly affecting the synovial lining of knee joint causing joint pain and swelling with or without movement restriction. Lesion chiefly consists of proliferating mature fat infiltrating the hypertrophic synovial villi. Synovial lipomatosis may be primary or secondary to osteoarthritis of the affected joint. Thus any one’s presence favours the others. Case reportThis is a very rare case of synovial lipomatosis in bilateral knee joints affected with osteoarthritis in an elderly female patient. She had history of pain and swelling of both knee joints for a long duration with recent exacerbation and disability in daily life activities. Her X-ray images showed features of degenerative changes suggestive of osteoarthritis. She was planned for arthroplasty and perioperatively a soft tissue mass was recovered from both her knee joints. Histopathological study of the excised tissue showed characteristic features of synovial lipomatosis with chronic synovitis. ConclusionThough most cases of synovial lipomatosis occur de-novo it may be associated with a degenerative process. Possibly it occurs as a secondary process following a chronic joint disease like osteoarthritis.