Case Report: Synchronous bilateral lipoma arborescens of the bicipitoradial bursa

Background: Lipoma arborescens (LA) is an infrequent benign tumor made of mature sub-synovial fatty cell proliferation that may arise into the synovial joint, the bursae or the tendon sheaths. This condition affects mainly the knee joint, but the bicipitoradial bursa is an exceptional location. We report herein a case of a synchronous bilateral (LA) of the bicipitoradial bursa. Case presentation: A 52-year-old patient, with no medical history, presented with a swelling of both front arms that had been progressing for nine years. Physical examination showed a mass in the antecubital fossae of 3cm on the left side and 0.5cm on the right side. Both masses were tender, well-defined, fixed, without inflammatory signs and painful on elbow flexion. A magnetic resonance imaging (MRI) scan was performed, revealing the presence of a septate soft-tissue mass of the distal portion of the brachial muscle of 70x46x27mm. This mass had a heterogeneous fat signal in its depth and a homogeneous fat composition on the outside. The diagnosis of liposarcoma was suspected. The patient underwent surgery to remove both masses. Gross examination showed a characteristic frond-like or digitiform pattern. Microscopical examination demonstrated papillary proliferation of the synovial villi. The final diagnosis was of LA. The patient had no complications and there was no recurrence of LA. Conclusions: LA is a rare condition, and the bicipitoradial bursa is an exceptional location. Histological confirmation is mandatory to correct the diagnosis.