Cytologic aspect of fibrolamellar hepatocellular carcinoma in fine-needle aspirates

This is a review of the cytologic and clinicopathological findings seen in a series of six fibrolamellar hepatocellular carcinomas (FL‐HCC) studied by means of fine‐needle aspiration (FNA). A comparison of several cellular measurements (cell, nuclear and nucleolar sizes, and N/C ratios) of FL‐HCC, ordinary hepatocellular carcinoma (O‐HCC), and normal hepatocytes was also carried out in order to find out if these figures could be of help in the cytologic diagnosis. Aspirates were made up of a rather monotonous population of large discohesive cells resembling the morphology of the oncocytes seen in thyroid aspirates; trabecular arrangement of tumor cells was not observed. Cytoplasmic pale bodies and hyaline cytoplasmic bodies were seen in variable quantities. Microbiopsies displaying the fibrolamellar pattern were observed in four cases. FL‐HCC individual tumor cells were larger than individual O‐HCC tumor cells (P < 0.001), as were nuclear (P < 0.007) and nucleolar sizes (P < 0.001), but N/C ratio of O‐HCC was higher than the N/C ratio of FL‐HCC (P < 0.005). Based on the findings, a single cell aspirated from an FL‐HCC is three times the size of a normal hepatocyte and 1.60 times the size of a single cell aspirated from a well‐differentiated O‐HCC. The cytologic findings of FL‐HCC are very characteristic and permit a correct diagnosis of this liver malignancy, provided the cytopathologist is aware of the clinical, demographic, CT‐image, biochemical, and pathological features of this neoplasm. Diagn. Cytopathol. 21:180–187, 1999. © 1999 Wiley‐Liss, Inc.