[A patient with abdominal actinomycosis--diagnostic problems]

The difficulties in diagnosis of abdominal actinomycosis are presented. Clinical manifestations and colonoscopy suggested malignancy. Final diagnosis was made on the basis of pathological assessment of resected sigmoid. Authors underline that in case of "negative" pathomorphological results of material obtained during endoscopy from lesions suspected, benign disease should be consider including anctinomycosis and intraoperative pathomorphological examination should be performed.