Abnormality of the infrapatellar fat pad (Hoffa's fat pad) in a patient with HIV: MR findings with histological correlation

There are various musculoskeletal manifestations of HIV infection. A recent report of 6 cases has described a strong relationship between HIV infection and increased signal intensity in Hoffa's fat pad on fluid sensitive sequences. These changes were attributed to chronic inflammation. We describe a case of MRI signal abnormality of Hoffa's fat pad in a patient with HIV infection, where biopsy was performed and confirmed non-specific inflammation.