Actinomycosis of the cholecystic duct: case report and review.

Actinomycosis of the gall bladder, cholecystic duct or common bile duct is rare, with only 16 cases reported to our knowledge. We report a case of actinomycosis in the cholecystic duct remnant of an 80-year-old woman with a history of cholecystitis, choledocholithiasis and cholecystoduodenal fistula requiring cholecystectomy and fistula closure three years prior. Histologic sections of the cystic duct remnant showed several dense basophilic masses containing numerous, dark blue, Gram-positive branching bacilli compatible with actinomycotic granules. Fluorescent antibody staining was positive for Actinomyces naeslundii. Staining for acid-fast bacilli was negative. The pathogenesis, presentation, diagnosis and management of abdominal actinomycosis with specific reference to disease involving the gall bladder are discussed.