Adenocarcinoma of the ileum with an enterotubal fistula presenting as an adnexal mass

Small bowel adenocarcinomas account for 3% of gastrointestinal malignancies, and 20 to 25% of these arise in the ileum. Clinical presentation is variable, and early diagnosis is difficult. A 56-year-old postmenopausal woman presented with crampy abdominal pain, anorexia, and weight loss. Pelvic examination and ultrasound revealed a 6 x 8-cm complex right adnexal mass. At laparotomy, en bloc resection of the right adnexa and the densely adherent ileal segment was performed along with a hysterectomy and a left salpingo-oophorectomy. The final pathology showed a moderately differentiated invasive adenocarcinoma of the ileum with a malignant enterotubal fistula. This is the first case reported in the literature of an ileal adenocarcinoma with a tubal fistula masquerading as an adnexal mass.