Fine-needle aspiration biopsy of liver masses: Diagnostic value and reproducibility of cytological criteria

There are many helpful cytological criteria for the diagnosis of liver fine -needle aspiration biopsies (FNABs), but none of them are pathognomonic of primary or metastatic tumors. We analyzed the diagnostic value and reproduc ibility of 28 cytological parameters in FNABs from 140 hepatic masses, incl uding 29 benign lesions, 49 hepatocellular carcinomas (HCC's), and 62 metas tatic tumors, encompassing 48 adenocarcinomas (ACAs). Five different observ ers evaluated each sample, and the interobserver and intraobserver agreemen t was studied. Multivariable analysis showed that the criteria more closely , associated with malignancy were irregular nuclear contour, three-dimensio nal cell groups, and atypical naked nuclei. Capillaries separating tumor ce lls and granular cytoplasm were strongly associated with HCCs, while eccent rically placed nuclei and necrosis were most commonly seen in ACAs and in m etastatic tumors. The intraobserved and interobserver agreement was excelle nt for the final cytological diagnosis, and there was fair to very good int erobserver agreement for 22 of the 28 criteria studied. Architectural featu res were less reproducible than pure cytological criteria. Intraobserver va riability Tvas not influenced by the years of experience in the field. A pr ecise and strict definition of terminology rendered a better reproducibilit y of the cytological criteria. (C) 2001 Wiley-Liss, Inc.