Actinomycosis of the greater omentum

Abdominal actinomycosis: a rare complication after laparoscopic gastric bypass

A 33-year-old, morbidity obese woman underwent a laparoscopic Roux-en-Y gastric bypass in November 2004. She presented 18 months later with a history of recurrent pain in the upper region of the abdomen and severe vomiting. Radiologic and endoscopic evaluations revealed wall thickening in the transverse colon and a solid tumor near the liver. Therefore, a sonography-guided biopsy of the tumor was performed. Cytopathological examination revealed actinomycosis. Thus, therapy with penicillin was started, after which the parameters associated with the infection decreased. The symptoms persisted, however, and the decision was made to operate on the patient to resect the abdominal masses. Nearly 90% of the masses could be removed. Histological analysis showed a fibro-productive inflammation with an actinomycotic etiology. Antibiotic therapy with penicillin was continued for 6 months. Actinomycosis must be considered in the differential diagnosis of patients with abdominal mass, wall thickening of the intestine, and other such symptoms, including abdominal pain following bariatric surgery, even many years after the intervention.

Abdominopelvic actinomycosis involving the gastrointestinal tract: CT features

PURPOSE

To assess the computed tomographic (CT) features of abdominopelvic actinomycosis involving the gastrointestinal tract.

MATERIALS AND METHODS

CT scans were analyzed in 18 patients with pathologically proved abdominopelvic actinomycosis involving the gastrointestinal tract. Eight patients had a history of using intrauterine contraceptive devices. Bowel site, wall thickness, length, bowel involvement patterns, inflammatory infiltration, and features of peritoneal or pelvic mass, if present, were evaluated at CT.

RESULTS

Of the gastrointestinal tract, the sigmoid colon was most commonly involved (50%). All patients showed concentric (n = 15) or eccentric (n = 3) bowel wall thickening, with a mean thickness of 1.2 cm and a mean length of 8.3 cm. The thickened bowel enhanced homogeneously in nine patients and heterogeneously in the other nine. Inflammatory infiltration was mostly diffuse and severe. In 17 patients, a peritoneal or pelvic mass (mean maximum diameter, 3.2 cm) was seen adjacent to the involved bowel and appeared to be heterogeneously enhanced in most cases; infiltration into the abdominal wall was seen in four patients.

CONCLUSION

Actinomycosis should be included in the differential diagnosis when CT scans show bowel wall thickening and regional pelvic or peritoneal mass with extensive infiltration, especially in patients with abdominal pain, fever, leukocytosis, or long-term use of intrauterine contraceptive devices.

Mesenteric actinomycosis

We report a case of abdominal actinomycosis demonstrated on computed tomography (CT) as an isolated mesenteric mass with radiating linear and nodular densities. The lesion mimicked a mesenteric tumor with desmoplastic reaction. The clinical and radiological features of this uncommon entity are reviewed.