Hepatic Pseudolymphoma with Fluorodeoxyglucose Uptake on Positron Emission Tomography

A 69-year-old woman with chronic hepatitis B was admitted to our hospital with a hepatic tumor. The levels of 2 tumor markers, carcinoembryonic antigen and carbohydrate antigen 19-9, were slightly elevated; however, the α-fetoprotein and protein levels induced by vitamin K antagonist II were within the normal limits. Abdominal ultrasonography showed a well-defined peripheral hypoechoic mass that was isoechoic and homogeneous on the inside. Computed tomography showed a poorly enhanced tumor of 13 mm in diameter in the 5th segment of the liver. Fluorodeoxyglucose positron emission tomography showed a slight uptake (maximum standard uptake value 3.4) by the hepatic tumor. These findings suggested cholangiocellular carcinoma, and we performed anterior segmentectomy of the liver. A histopathological examination showed a hepatic pseudolymphoma. The patient's postoperative course was uneventful, and she remains alive without recurrence 5 months after undergoing surgery. In most cases, hepatic pseudolymphoma is preoperatively diagnosed as a malignant tumor and a definite diagnosis is made after resection. It is therefore necessary to consider hepatic pseudolymphoma as a differential diagnosis in patients with hepatic tumors.