“GIANT SYNOVIAL CYST OF THE HIP JOINT”- AN IMPORTANT BUT RARE DIFFERENTIAL DIAGNOSIS OF AN INGUINAL SWELLING.

Abstract

Giant synovial cyst is commonly seen in association with rheumatoid arthritis. The Baker’s cyst around the knee is the commonest example but it has also been described at the elbow and hip. The possibility of a synovial cyst around the hip is unfamiliar to most clinicians including those who regularly deal with inguinal swellings and those specialising in musculoskeletal conditions. This is often overlooked as a cause of symptoms in inguinal area and lower limb.

We present a report on two patients in whom abnormal pulsatile masses in the groin caused diagnostic difficulty. Patients were initially admitted under vascular surgeons with a clinical diagnosis of aneurysm. Ultrasound examination was useful in excluding aneurysm. Detailed clinical examination revealed painful restricted hip movements and an X–ray showed evidence of arthritis in hip joint. CT Scan confirmed it to be a synovial cyst. Computed Arthrotomogram or Arthrography showed communication of the cyst with hip joint.

Synovial cysts and iliopsoas bursa enlargement may be more common than previously reported. They may present as a pulsatile mass due to close proximity to femoral vessels and should be considered as a differential diagnosis in patients with unusual inguinal swelling.