Retrospective study of cytologic features of well-differentiated hepatocellular carcinoma in dogs



Carlo Masserdotti, Laboratorio Veterinario San Marco, Via Sorio 114/C, 35141 Padua, Italy




Cytologic diagnosis of hepatocellular carcinoma is possible when hepatocytes have prominent criteria of malignancy, but is problematic when hepatocytes have a relatively normal morphologic appearance.


The aim of this study was to determine the cytologic features of histologically confirmed well-differentiated hepatocellular carcinomas (WD-HCC) in dogs to develop reasonable criteria for an accurate diagnosis when obvious criteria of malignancy in hepatocytes are lacking.


Slides of ultrasound-guided fine-needle aspirates of 15 histologically confirmed WD-HCC in dogs were evaluated retrospectively using a scoring system (0–3) established for 33 cytologic features. For comparison, 15 cytologic samples of non-nodular non-neoplastic liver were evaluated using the same criteria. Statistical analysis included multiple hypothesis testing using the Benjamini–Hochberg method or false discovery rate control to correct for multiple comparisons.


The most significant and useful cytologic features in the diagnosis of canine WD-HCC were dissociation of hepatocytes, acinar or palisading arrangements of neoplastic cells, and the presence of naked nuclei and capillaries, together with mild anisocytosis, anisokaryosis, multinuclearity, and increased N:C ratios.


Cytologic features of canine WD-HCC were determined. Further studies are warranted to compare these cytologic criteria among WD-HCC, hepatomas, and hyperplastic nodules and to examine co-variance of the 33 cytologic features.