Lipoma arborescens-MRI

51 year old male with clinical history of ? Psoriatic arthritis.: Evidence of extensive fluid in the knee joint distending the suprapatellar bursa and medial/lateral recess, along with significant synovial hypertrophy and thickening.   There is vilous filiform pattern of synovial hypertrophy with areas of lipomatous signal on all sequences possible lipoma arborescens.

Lipoma arborescens is a rare intraarticular lesion characterized by villous Iipomatous proliferation of the synovium, usually involving the suprapatellar pouch of the knee joint. A patient with the condition typically has a slow increase in painless swelling of the knee for many years, accompanied by intermittent effusions. MR imaging findings of this rare disease. which probably are diagnostic include a villous like synovial mass with a signal intensity similar to that of fat on all pulse sequences with associated joint effusion.