Fatemeh Mahjoub - Ward of Pathology, Markaze Tebbi Koodakan, Tehran University of Medical Sciences,Tehran, Iran
Farhang Ghanipour - Ward of Orthopedics, Markaze Tebbi Koodakan, Tehran University of Medical Sciences,Tehran, Iran
Nasrin Samadi - Ward of Pathology, Markaze Tebbi Koodakan, Tehran University of Medical Sciences,Tehran, Iran

Lipoma arborescens, also known as villous lipomatous transformation of synovium is an unusual fatty lesion of joint. This disorder is characterized by a diffuse increase in the quantity ofsubsynovial fat in supra-patellar region which bulges the overlying synovial lining and produces avillous architecture. Hereby we report a case of Lipoma arborescens in an eleven year old boy with a history of supra-patellar swelling of left knee since a year ago. Also, he had a vague history of trauma beforeleft knee swelling. Radiological and histopathologic features of our case are discussed alongsidefull review of literature. This disorder is an unusual lesion and occurs mainly in middle aged men and is rare in pediatric age group.

Lipoma arborescens, Knee joint, Pediatric age group