[Actinomycosis of the colon as a rare differential diagnosis of colonic carcinoma].

INTRODUCTION: Abdominal actinomycosis is an uncommon disease. Nevertheless it should be considered in case of unclear tumor-like abdominal masses.
METHODS: We report a case of a 49-year-old patient with an intrauterine device. The patient was submitted with a solid and painful tumor in the upper abdomen. After sonography, computerized tomography, gastroduodenoscopy and colonoscopy the preoperative presumptive diagnosis was a carcinoma of the transvers colon invading the abdominal wall. Pathological examination after a right hemicolectomy surprisingly revealed an actinomycosis.
RESULTS: Based on this case diagnostic tools and therapeutic options of actinomycosis of the colon are discussed.
CONCLUSIONS: This case illustrates the importance to consider the possibility of actinomycosis when finding an unclear abdominal mass. After a surgical excision an abdominal actinomycosis requires antibiotic therapy.