Actinomycosis of the colon with invasion of the abdominal wall: An uncommon presentation of a colonic tumour

Actinomycosis is an uncommon chronic suppurative infectious disease that is caused by Actinomycetes organisms, which are gram-positive, microaerophilic, anaerobic bacteria. The most common type causing disease in humans is Actinomyces israelii. This organism is a commensal of thehumanmouth and is seldom pathogenic. Whenit does cause disease, however, three main clinical types of involvement are recognized including cervico-facial, thoracic and abdominal actinomycosis. Herein, we present the case of a 79-year-old male patient who underwent surgical exploration following presentation with abdominal pain and an abdominal mass, initially thought to be a malignancy. Pathologic examination confirmed this as a case of abdominal actinomycosis. This diagnosis should always be included in the differential diagnosis of patients who present with an infiltrative abdominal mass. (C) 2010 Surgical Associates Ltd. Published by Elsevier Ltd. Open access under CC BY-NC-ND license.