Jia-Jie Yu

Immunohistochemistry (IHC) is a vital tool to distinguish tumor metastases from primary lesions in addition to morphologic analysis. In this study, a 64-year-old female with a past surgical history of lung adenocarcinoma 11 years ago was presented with recurrence of liver nodular lesions after multiple surgical procedures, including the Whipple procedure for pancreatic head adenocarcinoma and cytoreductive surgery for liver metastasis. Liver biopsy and review of the previous specimens, based on IHC analyses, suggested heterochronous metastases of lung adenocarcinoma to the digestive systems in a long-time span, instead of primary pancreatic adenocarcinoma. This case demonstrates the potential for misdiagnoses from morphologic analysis alone and suggests the necessity of IHC analyses to avoid misjudgment on tumor phenotypes, when a previous oncologic history is presented.

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. A 42-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.