A mesothelial cyst of the round ligament presenting as an inguinal hernia after gonadotropin stimulation for in vitro fertilization.

Objective: To report the case of a round ligament cyst which, as the result of gonadotropin stimulation for IVF, simulated an incarcerated inguinal hernia.

Design: Case report.

Setting: A private infertility center and a university hospital.

Patient(s): A 31-year-old woman who developed left lower quadrant pain after gonadotropin stimulation for IUI and a tender left inguinal mass after increasing ovarian stimulation for IVF/intracytoplasmic sperm injection.

Intervention(s): Surgical excision of a mesothelial cyst of the left round ligament and exploration of the left inguinal canal.

Main Outcome Measure(s): Successful surgical excision of left inguinal mass.

Result(s): Resolution of symptoms.

Conclusion(s): Mesothelial cysts of the round ligament should be included in the differential diagnosis of inguinal masses in women. Gonadotropin stimulation might cause previously unrecognized cysts to simulate an incarcerated inguinal hernia, necessitating surgical repair.