Spontaneous abdominal wall endometriosis: A case report

Abdominal wall endometriosis (AWE) is a rare type of endometriosis, with an incidence ranging from 0.1% to 0.4%. It requires a high index of suspicion to avoid delays in diagnosis and treatment. This case is rather special because AWE occurred without a history of abdominal surgery or pelvic endometriosis. Herein, we report the case of a 48-year-old para-3 woman with localised cyclical abdominal pain associated with abdominal distension. On assessment during menstruation, there were localised tenderness at the right suprapubic area and a non-tender suprapubic mass corresponding to a 14-week-sized gravid uterus. An ultrasound revealed the presence of a heterogeneous hypoechoic lesion at the subcutaneous layer of the right suprapubic region sized 1.8×3.2×4.4 cm with poor demarcation. There were also multiple uterine fibroids varying in size and location. She underwent exploratory laparotomy, total abdominal hysterectomy with bilateral salpingo-oophorectomy and abdominal wall mass resection. Intraoperatively, the right abdominal wall mass measuring 6x5 cm and involving the subcutaneous layer was found to adhere to the rectus sheath with some chocolate-stained areas without connection to the peritoneal cavity. Additionally, multiple uterine fibroids were noted. There was no pelvic endometriosis, and the other pelvic organs were normal. The histopathological diagnosis of the abdominal wall mass was endometriosis. AWE should be one of the differential diagnoses even in the absence of previous surgery when encountering a patient with an abdominal wall mass especially when it is related to the menstrual cycle.