[A case of actinomycosis of gallbladder presenting as acute cholecystitis].

Actinomycosis is a chronic suppurative and granulomatous disease, characterized by the formation of abscess, draining sinuses, abundant granulation, and dense fibrous tissue. Actinomycosis of the gallbladder is extremely rare. We report a case of an 56-years old man who abruptly presented with right upper quadrant abdominal pain. Abdominal CT showed that the gallbladder had 2 cm sized stone and an edematous thick wall. Our preoperative diagnosis was acute calculous cholecystitis. After the management of acute cholecystitis, laparoscopic cholecystectomy was performed but converted to open surgery due to severe adhesion to liver and greater omentum. Partial cholecystectomy was performed. Histologic section of the gallbladder showed sulfur granule with gram-positive branching bacilli compatible with actinomyces. After cholecystectomy, the patient received intravenous penicillin G for 2 weeks, followed by oral penicillin for 3 months.