Aileen Wee, MB,BS, FRCPath, FRCPA*
Yong Loo Lin School of Medicine**
*Professor and Senior Consultant, Department of Pathology
**National University of Singapore, National University Hospital, 5 Lower Kent Ridge Road, Singapore, 119074 Email : firstname.lastname@example.org Correspondence : Aileen Wee, MB,BS, FRCPath, FRCPA Received : 20 February 2015 ; Accepted : 13 March 2015
Focal liver lesions can be solitary or multiple, solid or cystic, congenital or acquired, and range from cysts, hamartomas, hyperplastic nodules and inflammatory entities to tumors and tumor-like lesions. The background liver may be normal or diseased. An algorithmic approach based on pattern recognition and cell profiling is outlined for the diagnosis of focal liver lesions with glandular features in small tissue samples from fine needle aspiration and core needle biopsy. The morphological categories for lesions with glandular phenotypes are (i) glandular (ducts, glands and/or mucin) pattern, including biliary and papillary patterns, (ii) hepatocellular and epithelioid patterns; (iii) mixed epithelioid-glandular (hepatobiliary) pattern; (iv) predominant cell profiles; and (v) cystic pattern. Hepatobiliary entities should be segregated before considering nonhepatobiliary
conditions. The main diagnostic issues are to distinguish cystic from solid lesions, primary from metastatic adenocarcinomas, poorly differentiated adenocarcinoma from poorly differentiated hepatocellular carcinoma; and to recognize rare glandular entities, mimics and pitfalls. Assessment of sample adequacy, key cytohistological features, and diagnostic utility of ancillary tests are addressed. Close clinicopathological correlation is mandatory before rendering a fi nal defi nitive diagnosis.