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.