Differential diagnostic dilemmas in malignant fine-needle aspirates of liver: a practical approach to final diagnosis.

We retrospectively reviewed two hundred malignant fine-needle aspirates of liver. Of these 49.5% were metastatic neoplasms, 32% were hepatocellular carcinomas, and 18.5% presented with diagnostic dilemmas. In less than half of these diagnostic challenges, differential diagnosis was between hepatocellular carcinoma and metastatic adenocarcinoma. The remainder of cases involved a variety of metastatic neoplasms. Cytomorphology in association with immunocytochemistry resolved the diagnostic problems in about half of the problematic cases. Three cases were undifferentiated and remained unclassifiable. We conclude that approximately 80% of malignant lesions of liver can be correctly diagnosed by thorough cytomorphologic analysis and good clinical correlation, and 20% pose differential diagnostic dilemmas.