Intra-articular lipoma of the knee joint located in the posterior compartment: A rare location

This report presents the case of a 51-year-old woman with intermittent left knee pain, especially during full flexion of the knee, which had been ongoing for 1 year. Magnetic resonance imaging (MRI) showed mild effusion and round mass at the posterior compartment without synovial changes. Computerized tomography (CT) indicated mass had homogeneous low attenuation and density measurement of -99.4±62.3 Hounsfield units (HU), correlated with a lipomatous lesion