A case of laparoscopic hepatectomy for a primary hepatic neuroendocrine tumor.

Neuroendocrine tumors (NETs) account for approximately 1-2% of all gastrointestinal tumors. In particular, primary hepatic NETs (PHNETs) are extremely rare. A 42-year-old female patient was given a diagnosis of liver tumor after a medical check-up with ultrasonography. An enhanced CT scan and MRI were suggestive for a hepatic hemangioma or adenoma, but the possibility of hepatocellular carcinoma could not be denied. Moreover, this tumor grew larger, so we performed a laparoscopic partial hepatectomy for the diagnosis and treatment of the patient. Pathological examination revealed that the tumor cells were spindle-shaped, forming glandular-tubular structures, and had less visible nucleoli and increased mitotic figures on H&E staining. Immunohistochemical findings indicated that CK19, MOC-31, CD56, synaptophysin, and chromogranin A were positive; CK7, AFP, and glypican-3 were negative; and the Ki-67 index was 3.6%, so the final diagnosis was a PHNET G2. PHNETs differ from other NETs, as they do not produce biologically active polypeptides or amines. As a result, there are no manifestations of carcinoid syndrome. In addition, PHNETs grow slowly, and most patients show no symptoms in the early stages. Laparoscopic hepatectomy is a very useful procedure for diagnosis and treatment in such cases and can be performed safely.