Lipoma arborescence of knee joint in an adolescent male patient: a case report

Abstract

A very uncommon benign synovial membrane tumor is called lipoma arborescens. It often affects a single articulation, the knee. Despite a conventional imaging assessment, the lesion’s histological analysis is still required for the ultimate diagnosis. A 15-year-old boy attended the outpatient clinic of the Lahore General Hospital Lahore, Pakistan with pain and swelling in his left knee that had been steadily worsening over the previous 4 years. There were no concomitant prodromal symptoms, and the swelling was soft and non-tender while also inhibiting knee flexion. Soft tissue shadows were observed on radiographs. A large amount of subarticular erosion in the nearby tibial and femoral condyle was caused by the frond-like proliferation of fatty synovium, according to magnetic resonance imaging. Only the left knee joint showed focused areas of unusually elevated radionuclide uptake during the Technetium (Tc99m) bone scan. After an open synovectomy, the specimen underwent histological analysis, which revealed villiform fatty tissue, a hallmark of Lipoma arborescens coated by somewhat thicker synovium. Although infrequent, open synovectomy is currently the preferred course of treatment for lipoma arborescens, which should be taken into account when making a differential diagnosis of knee diseases. Approximately 3 months after surgery, the patient underwent his most recent follow-up and was asymptomatic with a small amount of joint effusion.