Extra-Articular Lipoma Arborescens Lipoma arborescens is a rare articular lesion consisting of subsynovial villous proliferation of mature fat cells, usually involving the suprapatellar pouch of the knee joint. It primarily involves the knee joint, with rare occurrences in the periarticular bursae and tendon sheaths.
The Latin term ‘arborescens’ means ‘tree-like appearance’, describing the characteristic villous and frond-like morphology of this condition. While the exact cause of lipoma arborescens is unknown, it has been hypothesised to be a nonspecific reactive synovial fatty proliferation in response to chronic traumatic or inflammatory stimuli.
This entity can be confidently diagnosed by its characteristic features on MR imaging.
Stepan JG, Gelberman RH, Rubin DA, Osei DA. Extra-Articular Lipoma Arborescens of the Dorsal Aspect of the Wrist with Invasion of the Extensor Tendons. A Case Report. JBJS Case Connect, 2013 Mar 27; 3 (1): e30. [ Article ]