Endometriosis of the appendix causing small bowel obstruction in a virgin abdomen

A 29-year-old, otherwise well, nulligravid woman presented to the emergency department with 1-day history of generalised abdominal pain and vomiting. She had similar symptoms 6 months prior following recent menstruations, which resolved conservatively. She had no prior history of abdominal surgery or endometriosis. CT scan demonstrated distal small bowel obstruction. A congenital band adhesion was suspected, and she underwent prompt surgical intervention. During laparoscopy, a thickened appendix was adhered to a segment of distal ileum. There was blood in the pelvis. Laparoscopic adhesiolysis and appendicectomy were performed. Histopathology demonstrated multiple foci of endometriosis of the appendix with endometrial glands surrounded by endometrial stroma. Oestrogen receptor and CD10 immunostains highlighted the endometriotic foci. The patient made a good recovery and was referred to a gynaecologist for further management.