[Round ligament cyst simulating incarcerated inguinal hernia. Report of a case].

BACKGROUND Round ligament cysts are rare lesions, often diagnosed as irreducible inguinal hernias. Most patients are in the third to fourth decade of life, but they can occur in younger patients. They are usually clinically asymptomatic or tend to produce subtle symptoms such as pain, discomfort, or a feeling of heaviness, and swelling. Cysts should not be resized with the Valsalva manoeuvre. Ultrasound is the diagnostic method of choice. The definitive diagnosis is made during surgery, and confirmed by pathological examination. OBJECTIVE To present a case of round ligament cyst, initially diagnosed as an incarcerated inguinal hernia, and a review of the literature. CLINICAL CASE A 19 year-old female, who was admitted to the emergency department due to her current condition of 5 days of onset. She had an increased volume in right inguinal region that increased with physical exertion, throbbing pain, and nausea without vomiting. A right inguinal mass of approximately of 6cm in diameter was found, which was painful on mid-superficial palpation, reaching a pre-surgical diagnosis of incarcerated right inguinal hernia with an indication of surgical intervention. CONCLUSION Round ligament cysts are a rare pathology, often confused with incarcerated inguinal hernias. Although ultrasound is the study of choice, the final diagnosis is usually made during surgery and confirmed by histopathology.