Proportion of mast cells in normal canine hepatic cytologic specimens: comparison of 2 staining methods.

Abstract

BACKGROUND: Although the presence of mast cells is considered a normal finding in canine hepatic tissue, the normal proportion of these cells in cytologic specimens from normal livers was not previously established. OBJECTIVES: The objective of this study was to determine the normal proportion of hepatic mast cells in cytologic specimens from normal canine liver by the use and comparison of the May-Gr&#xfc;nwald-Giemsa and the Toluidine Blue staining methods. METHODS: The cytologic specimens obtained from fine-needle aspirates of livers of 13 healthy dogs were investigated by counting of hepatocytes and mast cells per high-power field (HPF, x40 objective). The ratio of mast cells/100 hepatocytes was then compared between the 2 staining methods. RESULTS: A median of 0.17 (range: 0-0.33) mast cells/100 hepatocytes and of 0.47 (range: 0-0.86) mast cells/100 hepatocytes was obtained with May-Gr&#xfc;nwald-Giemsa and Toluidine Blue stains, respectively. CONCLUSIONS: Toluidine Blue stain detects more hepatic mast cells than May-Grunwald-Giemsa in normal canine livers. With both stains, < 1% mast cells were detected in normal canine liver samples.