Abdominal wall endometriosis in a region distant to the caesarean section scar

Abdominal wall endometriosis (AWE) is a rare entity presenting as a painful lump with a cyclical pattern, associated with previous caesarean section (CS). AWE is typically located at the site of the CS scar. The diagnosis is challenging in the rare instance when AWE presents at a location distant to the CS scar. A 37-year-old patient presented to a general surgeon with a 2-year history of left-sided, periumbilical pain exacerbated during her menstrual periods. A 3 cm firm and tender nodule was noted clinically. Intraoperatively, the nodule involved the rectus muscle and infiltrated the peritoneum. Histology confirmed endometriosis, and the patient recovered uneventfully. The rarity of this clinical entity and the fact that AWE mostly presents to non-gynaecologists make the diagnosis challenging prolonging its physical and psychological morbidity. Thorough history-taking with emphasis on the pattern of pain and a previous history of CS should raise suspicion of AWE.