Abdominal actinomycosis simulating malignancy of the right colon

Abstract

Actinomycosis is a chronic, suppurative, and granulomatous disease caused by an anaerobic or microaerophilic gram-positive bacterium, Actinomyces israelii, manifesting itself as fistula, sinus, inflammatory pseudotumor, or abscess formation. The cervicofacial region (50 to 65%) accounts for the majority of the cases followed by abdomen (20%) (1–5). Abdominal infection mostly involves the cecal area and can simulate malignant tumor on clinical and radiological examinations (1, 4, 6, 7). The diagnosis is almost always ascertained after surgery and histopathological examination of the specimen. The purpose of this report is to emphasize the possibility of encountering an abdominal mass related to actinomycosis in emergency cases and the benefit of limited surgical procedure.

A 28-year-old man was admitted to emergency room with severe right lower abdominal pain, nausea, and vomitting of a few days’ duration. He had a 4-month history of decrease in appetite but no weight loss, bloating, and vague lower abdominal pain. His further medical history revealed hospitalization for pulmonary tuberculosis 9 years prior. He denied any surgical procedures. Physical examination disclosed fever (38◦C) and tachycardia (110/min). He was noted to have a distended abdomen with guarding and rebound tenderness, especially in the right upper and lower quadrants. No abdominal mass was palpated. Abnormal laboratory values included only a leukocyte count of 15,800/mm3. Abdominal ultrasound showed pelvic free fluid and an irregular mass in the right lower quadrant. The patient underwent an emergency laparotomy with the presumptive diagnosis of perforated appendicitis and related peManuscript received March 3, 2004; accepted August 18, 2004. From the Departments of *General Surgery and †Pathology, Inonu University School of Medicine, Malatya, Turkey. Address for reprint requests: Burak I¸sik, MD, Turgut Ozal Tip Merkezi, Genel Cerrahi AD, Elazig Yolu 15 km, Malatya 44280, Turkey; bisik@inonu.edu.tr. riappendicular abscess. Approximately 200 ml of greenish purulant fluid was aspirated from the pelvis. A large firm tumor extending from the ascending colon to the hepatic flexure involving the mesocolon was identified. The second portion of the duodenum was adherent to the posterior of the mass. The decision at this juncture was to perform a right hemicolectomy versus a hemicolectomy with Whipple procedure because of the duodenal invasion. We preferred to perform a right hemicolectomy with end-to-end ileocolonic anostomosis, leaving a macroscopically evident tumor on the duodenal serosa because of not having a malignancy confirmation of the mass. Further exploration of the abdominal cavity revealed no other pathological findings.