A 71-year-old man was diagnosed with elevated biliary enzyme levels by his previous doctor and visited the Niigata University Medical and Dental Hospital in June 2011. Abdominal computed tomography showed a 10 cm diameter mass, consisting of cystic and solid components in the right lobe with peripheral intrahepatic bile duct dilation. In addition, multiple lymph node swelling was observed around the aorta from the hilar region. It was considered to be intrahepatic cholangiocarcinoma or liver metastasis with abscess; however, percutaneous liver biopsy was performed before chemotherapy because liver resection was contraindicated. Moreover, no tumor cells were observed. Therefore, liver abscess was treated with antibiotics, and percutaneous transhepatic drainage was performed. Therefore, actinomycetes were detected from the liver tissue. When the antibiotics were changed to penicillin, the mass was remarkably reduced. Herein, we report a case of hepatic actinomycosis that is difficult to distinguish from malignant hepatic tumors.

Neuroendocrine tumor (NET) originates from neuroendocrine cells and frequently occurs in the small intestine, rectum, appendix, colon, and stomach; however, primary hepatic NET rarely occurs. A 60-year-old female patient with prior HBV infection was admitted to our hospital with a diagnosis of liver tumor. Enhanced computed tomography showed an enhancing nodule with washout, 20 mm in diameter. Gd-EOB-DTPA-enhanced magnetic resonance imaging also revealed low intensity in the hepatobiliary phase. With the diagnosis of hepatocellular carcinoma, she underwent liver resection. Immunohistochemical examination showed tumor cells were positive for chromogranin A, synaptophysin, CD56, and CK7; therefore, she was diagnosed as primary hepatic NET. Despite the development of novel molecular target drugs against NET, liver resection remains the only radical treatment for primary hepatic NET, and she is still alive without recurrence 3 years postoperatively. Here, we report the primary hepatic NET mimicking hepatocellular carcinoma in a patient with prior HBV infection.

Primary hepatic neuroendocrine cancer (NEC) that coexisted with hepatocellular carcinoma (HCC) is very rare. Even though a 68-year-old woman with liver cirrhosis with HCC had been treated with transcatheter arterial chemo-embolism and radiation, her cancer progressed rapidly with metastasis, without AFP elevation. The autopsy result showed that she had primary hepatic NEC only, with lymph node and peritoneal metastases; however, she had no viable HCC. Her HCCs became necrotic with repeated treatment, but the viable NEC coexisted with necrotic tissue of the primary HCC. These findings suggest that NEC was transformed from tolerated HCC to newly occurring during repeated treatment.

Relative dose intensity (RDI) is the ratio between the delivered dose intensity and the standard dose. Maintaining high RDI has been shown to improve clinical outcomes in various cancers. The dose of lenvatinib was determined according to patient's weight (12 mg/day for ≥60 kg or 8 mg/day for <60 kg); therefore, RDI could not reflect the actual treatment intensity in some cases. Here, we evaluated the utility of dose intensity/body surface area ratio (DBR). The difference in PFS between patients with high RDI (≥0.67) and low RDI (p = 0.0534) was not significant, whereas patients with high DBR (≥240) showed significantly better PFS than those with low DBR (p < 0.0001). DBR may be more appropriately used in assessing the lenvatinib treatment intensity as compared with RDI.