Abdominal Actinomycosis Mimicking Malignancy

A 76-year-old woman presented to our emergency department with hard periumbilical mass around irreducible umbilical hernia. Abdominopelvic computed tomography scan revealed large abdominal wall tumor, adherent to the small and large intestine, with a solitary 4-cm liver lesion in the right lobe. En bloc resection including umbilical skin, rectus muscle, infiltrated jejunum, and transverse colon was made with direct closure of the abdominal wall defect. Simultaneous excision of the liver lesion was also performed. The diagnosis was made but not until histopathological analysis. It revealed chronic inflammation and the presence of Actinomyces in the abdominal mass as well as in the liver lesion. The purpose of this report is to introduce readers to the differential diagnosis of this rare disease and thus enable them to recognize findings which would lead them to interpret this condition as actinomycosis.