[A case of abdominal actinomycosis presenting as mesenteric mass]

Actinomycosis is an indolent, slowly progressive infection caused by Actinomyces species and usually results in the formation of characteristic clumps called sulfur granules. Depending on the site of primary infection, it is generally classified as cervicofacial, thoracic, and abdominal type. Abdominal actinomycosis is often difficult to diagnose before operation because of its infrequent and chronic disease progression without any characteristic clinical features. In principle, diagnosis is based on histologic demonstration of sulfur granules in pus or surgically resected specimen, and the treatment consists of long-term antibiotic therapy coupled with or without surgical resection. We report a case of abdominal actinomycosis presenting as mesenteric mass adhering to small bowel confirmed by laparoscopic exploration and biopsy. Treatment with intravenous penicillin for 4 weeks followed by additional oral therapy for 11 months resulted in clinical resolution.