| Summary points: | A 27-year-old, nulliparous, Caucasian woman presents to the surgical admissions unit with a 2-day history of an acutely painful swelling in her right groin that was tender to touch and made worse by lying down. Medical history, current medications, physical examination, surgical exploration of the groin, histological examination of the excised tissue and mass, and outpatient follow-up are described. The author discuss an unusual case of endometriosis presenting as an acute groin swelling, which should be considered as a differential diagnosis in women of childbearing age. |