Lipoma arborescens: an unusual case of knee swelling.

To cite: Sarawagi R, Vijay S, Kumar Reddy A, et al. BMJ Case Rep Published online: [please include Day Month Year] doi:10.1136/bcr-2014203686 DESCRIPTION Lipoma arborescens is a rare condition of unknown aetiology with benign diffuse villous proliferation of the synovium characterised by replacement of the subsynovial tissue by mature adipocytes. The knee is the most commonly involved joint. A 56-year-old man with a history of trivial trauma 5 years ago, came with gradually increasing pain and swelling in the right knee. On examination there was a diffuse swelling of the right knee predominantly on the lateral aspect which was doughy in consistency with limited range of movements. The left knee was normal.