RESUMEN
Actinomycosis is a chronic suppurative and granulomatous disease caused by a Gram-negative anaerobic bacterium, Actinomyces israelii, which is among the normal flora of the oral cavity and gastrointestinal tract of humans and animals. It is characterized by sulfur granule formation and can involve the cervicofacial area, chest, abdomen, and pelvis. The most common predisposing factors are the presence of an intrauterine contraceptive device, previous trauma, appendectomy, colon diverticulum, and gastrointestinal perforation. Primary gastric actinomycosis is an extremely rare disease. Three cases of gastric actinomycosis have been reported in people who had a subtotal gastrectomy for stomach cancer in Korea. We report a case of primary gastric actinomycosis in a 59-year-old man with untreatable hepatocelluar carcinoma. His actinomycosis was cured with penicillin therapy.