Abstract

Background: Cholangiocarcinoma is a relatively rare form of adenocarcinoma which may resemble adenocarcinoma of pancreatobiliary origin or adenocarcinomas from many other sites in the body. As a result, its diagnosis relies mainly on clinical history and morphology.

Case: A 64-year-old male with cirrhosis and worsening liver failure underwent fine needle aspiration of a radiologically detected liver mass. Cytological material showed a monomorphic population of cells arranged singly and in clusters, reminiscent of a neuroendocrine tumour (NET). Cell block morphology added to the diagnostic dilemma by showing a delicate vasculature among the tumour cells. Immunohistochemistry on the cell block revealed that cells were positive for CK7 and CK19 and negative for synaptophysin and chromogranin, thereby pointing towards a pancreatobiliary origin for the tumour and excluding an NET.

Conclusion: In the case of liver aspirates, even when encountering confusing morphological entities, it is imperative to keep in mind the possibility of a rare neoplasm such as cholangiocarcinoma. In the absence of core needle biopsy, cell block sections prepared from aspirated material can provide appreciable immunohistochemistry results to resolve the diagnostic dilemma.

Keywords: cholangiocarcinoma; endoscopic ultrasound guided aspiration cytology; immunohistochemistry; neuroendocrine tumour.