A patient with painless intractable knee effusion due to secondary lipoma arborescens: A case report

Lipoma arborescens (LA) is a benign lesion of the knee with replacement of the subsynovial tissue. Clinically, the affected joint develops intractable knee effusion without much pain. The secondary type of LA is often associated with an underlying inflammatory condition and often occurs at elderly persons. Magnetic resonance imaging can easily detect this lesion with its characteristic frond-like appearance on T1- and T2-weighted images and LA has the same signal intensity as fat on T1- weight images. The choice of treatment is open or arthroscopic synovectomy. The underlying precipitating factor accompanying secondary LA should also be corrected, so as to reduce further progression.