Misdiagnosis of Primary Hepatic Neuroendocrine Carcinoma: A Case Report and Literature Review

Abstract Background: Primary hepatic neuroendocrine carcinoma (PHNEC) is relatively rare and has high malignancy and poor prognosis, but the rate of clinical diagnosis is low. The clinical symptoms, signs, and ultrasound images are not specific. Diagnosis is mainly based on pathological manifestations and immunophenotyping analysis. Here, we present a case of PHNEC with rectal adenoma.Case presentation: A 63-year-old male patient complained of dull pain and discomfort in his right upper abdomen that had persisted for over 1 month. This individual was initially diagnosed with rectal cancer with liver metastasis because of unclear and inconclusive imaging examination results. The biopsy of rectal polyps indicated tubular villous adenoma, and the liver biopsy and immunohistochemical examinations suggested PHNEC.Conclusions: When a patient has not been diagnosed with hepatitis or cirrhosis, the AFP value is not high, and imaging shows solid space-occupying lesions, liquefaction, and clear liver tumor boundaries, we can exclude tumors of non-hepatic origin using gastroscopy, colonoscopy, and PET-CT, and other tests. We can then consider Primary hepatic neuroendocrine tumor and confirm this with pathological examinations and immunophenotyping.