Unraveling the Mystery of Parosteal Lipoma of the Distal Femur: A Rare Case Report.

Abstract

Among all the primary bone tumors and all the type of lipomas, parosteal lipomas stand for <0.1% and 0.3%, respectively, which mostly consists of fully developed adipose tissue with or without a bony component. Patients with this tumor usually have bony lesions (59.2%), necessitating a differential diagnosis of malignant tumors. Here, we analyze a case report of a 9-year-old boy, who developed a parosteal lipoma in the distal femur. A massive, well-defined, lobulated, mostly fat-intensity lesion of 10 cm by 6 cm by 8 cm was seen on an magnetic resonance imaging scan of the right distal femur. After the lump was removed, the pathologically reveals a parosteal lipoma without any malignant changes. Finally, it should be noted that parosteal lipomas are less common neoplasias with no known malignant potential. Since these tumors can be removed with mild impact to nearby structures, the lower limb's functionality is kept intact.