Lipoma arborescens is a rare case affecting the synovial linings of the joints and bursae, with 'frond like' depositions of fatty tissue. They account for less than 1% of all lipomatous lesions.
Clinical presentation
Clinically presented by painless joint swelling, frequently with effusion, typically in the 5th - 7th decades. Usually these lesions are sporadic, however they can be seen in the setting of osteoarthritis, collagen vascular disorders or previous trauma.
The most common site of involvement is suprapatellar bursa of knee joint, and the disorder is usually unilateral . Occasional reports of hip, shoulder, wrist elbow are also reported. Other joint involvement is uncommon. Involvement of tendon sheath is even rarer.
Treatment and prognosis
The condition is benign and is cured by synovectomy. Recurrence is uncommon
For MRI images (of ankle involvement):