Thoracoabdominal actinomycosis associated with laparoscopic cholecystectomy and mimicking metastatic pulmonary malignancy

Actinomyces naeslundii is rarely isolated in cases of actinomycosis. We present a case of thoracoabdominal actinomycosis caused by inadvertent enterotomy and gallstone spillage during a laparoscopic cholecystectomy. The actinomycosis initially presented as recurrent episodes of pneumonia, shortness of breath and unintentional weight loss. Initial CT imaging demonstrated pleural thickening along the right lung base as well as ill-defined consolidation in the right lower lobe. Repeat CT imaging showed progression of the mass-like region of consolidation with extrapulmonary spread to involve the abdomen, retroperitoneum and retrohepatic areas. Treatment involved intravenous antibiotics with concurrent abscess drainage followed by oral antibiotics.