Primary Hepatic Neuroendocrine Tumor Mimicking Ruptured Hepatocellular Carcinoma with AFP Elevation: A Case Report and Literature Review

Liver cancer is a common malignant disease in China, while the primary hepatic neuroendocrine tumor (PHNET) is extremely rare presented with various manifestations. We herein describe an interesting PHNET case, which was clinically diagnosed as hepatocellular carcinoma (HCC) based on strong clinical evidence and the national guideline, but confirmed to be PHNET by pathology. A42-year-old Chinese male was admitted for persistent upper abdominal pain, and CT scan revealed a huge liver tumor in the left lobe. The tumor presented attributes of tumor rupture, portal vein tumor thrombus, elevated serum AFP level, background hepatitis B virus infection history, and radiological features mimicking typical HCC. After left semi-hepatectomy was performed for curative treatment of the primary "HCC", the pathology demonstrated the correct diagnosis be poorly differentiated neuroendocrine carcinoma (NEC). The immunohistochemistry assays showed positive neuroendocrine markers of CgA and Syn and negative HCC markers of Hep Par 1 and GPC3, ruling out concurrent HCC. This case and literature review suggest that in spite of rare incidence, PHNET should be considered as a possible diagnosis when lacking a confirmative pathology result, even when sufficient evidence of typical presentation exist to establish the clinical diagnosis of HCC.