Introduction : Primary neuroendocrine tumor (NET) of the liver is a very rare neoplasm, requiring strict exclusion of possible extrahepatic primary sites for its diagnosis. This disease is often misdiagnosed as hepatocellular carcinoma or intrahepatic cholangiocarcinoma.

Methods : We analyzed our clinical experience of 14 patients with hepatic primary NET who underwent hepatic resection from January 1997 to December 2015. We excluded the cases in whom primary site was identified a few years later.

Results : The mean age of 14 patients was 51.6?3.0 years, with 8 males and 6 females. Of them, 11 patients underwent preoperative liver biopsy, which was correctly diagnosed NET in 7. Eleven patients R0 resection and 3 underwent R1 resection. Diagnosis of hepatic primary NET was confirmed immunohistochemically, as well as by absence of extrahepatic primary sites. All tumors were single lesions, of mean size 10.1?.8 cm, and all showed positive staining for synaptophysin and chromogranin. During a mean follow-up of 48.6?7.9 months, 6 patients died of multiple liver metastases after tumor recurrence, whereas the other 8 remain alive to date, making the 5-year tumor recurrence rate 50% and the 5-year patient survival rate 64.3%. Univariate analysis showed that Ki67 proliferative index was a risk factor for tumor recurrence. Octreotide scan was performed in 2 preoperatively and 2 postoperatively. One patient was responsive to transarterial chemoembolization (TACE) after recurrence, thus TACE was repeated 7 times so far.

Conclusions : Although primary hepatic NET is very rare, it should be distinguished from other liver neoplasms. The mainstay of treatment is curative liver resection.