Pseudo-cirrhosis: Metastatic neuroendocrine tumor mimicking hepatocellular carcinoma and liver cirrh
A previously well 60-year-old man presented with diarrhea to his general practitioner. He was found to have a painless epigastric mass and was referred to our institution for further investigation. Laboratory tests showed mildly elevated CA 19-9 (54U/mL), while other tumor markers were not elevated (AFP 5ug/L, CEA 2ug/L). All other tests such as full blood count, renal panel and liver function tests were within normal range. Contrast-enhanced magnetic resonance imaging (MRI) of the abdomen was performed. Features suggestive of cirrhosis were present: diffuse heterogeneity and nodularity of the liver parenchyma, left lobe hypertrophy, expanded gallbladder fossa and positive right hepatic posterior notch sign (Figure 1). On administration of intravenous contrast, there were areas of nodular arterial enhancement seen in both hepatic lobes. Significantly, there was a focus of arterial enhancement seen in segment 8 displaying characteristic enhancement pattern of hepatocellular carcinoma of arterial enhancement and early wash out (Figure 2). Imaging diagnosis of advanced, multi-focal HCC with nodal involvement in the background of liver cirrhosis was made. However, as the patient did not have risks factors for either liver cirrhosis or HCC, the patient underwent fine needle aspiration of the peri-pancreatic lymph nodes using endoscopic ultrasound guidance. Immunohistochemistry of the sample revealed atypical cells that were positive for cytokeratin (AE1/3), synaptophysin and chromogranin A, in keeping with neuroendocrine tumor. For tumor grading, ultrasound-guided core biopsy of one of the left lobe hepatic lesion was performed. Histopathology image (Figure 3) showed nests of tumor cells showing diffuse cytoplasmic synaptophysin staining, confirming the diagnosis of neuroendocrine tumor (NET). The included liver tissue showed no evidence of fibrosis to suggest liver cirrhosis. This case highlights a unique case of where NET liver metastases mimicked liver cirrhosis on imaging, not previously reported. In the age of non-invasive imaging diagnosis of HCC, such a presentation may lead to erroneous diagnosis and management. It illustrates the need for histological diagnosis in cases where imaging diagnosis is discordant with the clinical picture.