Diverticulitis Presenting as a Tubo-ovarian Abscess with Subsequent Colon Perforation

Abstract

Purpose: Diverticulosis is a common condition affecting 30-50% of adults over age 60 with 10-20% developing acute diverticulitis. In women, this can involve the left ovary as it lies in close proximity to the sigmoid colon where diverticula are most commonly located. We report a case of diverticulitis presenting as a tubo-ovarian abscess (TOA) with eventual free perforation of the colon. Case Report: A 63 year old woman presented to her gastroenterologist with vague persistent abdominal cramps. Imaging demonstrated a complex left ovarian cystic mass and elective surgery was recommended due to the suspicion of ovarian cancer. She presented to our hospital one month later because of increased abdominal discomfort and new onset of diarrhea. On physical exam, she was well-appearing with normal vital signs and an abdomen remarkable for mild distention, left upper quadrant, right lower quadrant and suprapubic tenderness without rebound. Labs were significant for hypokalemia, leukocytosis and hypoalbuminemia. An abdominal-pelvic CT scan confirmed a complex cystic left adnexal mass with surrounding inflammatory changes. The sigmoid colon adjacent to the pelvic mass contained a long segment of wall thickening without diverticula. Levaquin and flagyl were used to treat a presumed TOA. Evaluation of diarrhea with stool studies revealed fecal leukocytes but no pathogenic bacteria, parasites or C. difficile toxin. Flexible sigmoidoscopy was limited to 30 centimeters from the anal verge due to severe narrowing. Biopsies showed non-specific inflamed colonic mucosa. Three days later the patient's abdomen became more distended without increase in pain. Repeat CT scan showed free intraperitoneal air with a stable enhancing left pelvic mass inseparable from the adjacent sigmoid colon. Surgery was performed with removal of the pelvic mass and adherent sigmoid colon. Pathology revealed a 7cm mass encompassing the left fallopian tube and ovary associated with a perforated sigmoid diverticulum and features of an organized fibroinflammatory response. Discussion: Postmenopausal TOA is uncommonly due to pelvic inflammatory disease and most often is associated with a gynecologic malignancy. Early recognition of a TOA resulting from diverticulitis is crucial to prevent bowel complications such as stricture, fistula formation or free perforation. The finding of a thickened loop of sigmoid adherent to a pelvic mass even without diverticula visualized on CT, is suggestive of possible diverticulitis as the underlying pathology. Prompt recognition of this condition early in a patient's course will greatly improve the chances of a full and uncomplicated recovery.