Mimicry of a liver abscess as hepatocellular carcinoma

History: We report on a 82 year-old male who presented with chronic pain in the right upper abdomen, nausea and vomitus. An uncomplicated laparoscopic cholecystectomy occurred eight years and a hepatitis 60 years before. Clinical examination showed a normal abdominal status without palpable liver, spleen, enlarged lymph nodes or masses. He had no icteric skin and sclera. Investigations: The patient was afebril without leukocytosis. The tumour markers CEA, CA 19-9 and AFP were negative. Ultrasound of the abdomen showed a normal homogenous echo-texture of the liver without signs of cholestasis or cirrhosis. In segment 6 a 3cm large hypoechoic cystic formation with a central echogenic structure with acoustic shadowing was noted. Magnetic resonance revealed a 2,8 x 3,6cm large lesion in the dorsal region of segment 6 of the liver, infiltrating the perihepatic fat. Pathologic lymph nodes and metastases were not found. Diagnosis and treatment: At laparotomy, the tumour appeared to be malignant with invasion to the perirenal fat. Complete resection with negative margins included segment 6 of the liver and the adjacent fat (the kidney itself was not infiltrated). The cut specimen also showed signs of malignancy with central necrosis. However, histology of the resected specimen revealed a sterile liver abscess without malignancy, but with microscopic foreign bodies. The patient had an uneventful recovery without postoperative complications. Conclusions: This case report demonstrates the difficulty encountered in the differential diagnosis of inflammatory processes and malignant tumours. Chronic inflammatory changes may mimic solid neoplasms. Despite adequate magnetic resonance imaging and thorrough intraoperative examination, the correct diagnosis was finally found by histology. The most likely genesis of the abscess are lost gallstones during cholecystectomy.