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Proportion of mast cells in normal canine hepatic cytologic specimens: comparison of 2 staining methods
1San Marco Private Veterinary Laboratory, Padua, Italy.
Insights
Determining the normal proportion of mast cells in canine liver cytology is crucial. Toluidine Blue stain identifies more mast cells than May-Grünwald-Giemsa, with both showing less than 1% in healthy dogs.
Area of Science:
- Veterinary Pathology
- Canine Cytology
- Hepatology
Background:
- Mast cells are a normal finding in canine liver tissue.
- The precise proportion of mast cells in normal canine liver cytologic specimens was previously undefined.
- Establishing a baseline is essential for accurate diagnosis.
Purpose of the Study:
- To determine the normal proportion of hepatic mast cells in cytologic specimens from healthy dogs.
- To compare the efficacy of May-Grünwald-Giemsa and Toluidine Blue staining methods for mast cell detection.
- To establish a reference range for mast cells in normal canine livers.
Main Methods:
- Cytologic specimens were obtained via fine-needle aspiration from the livers of 13 healthy dogs.
- Hepatocytes and mast cells were counted per high-power field (HPF).
- The ratio of mast cells per 100 hepatocytes was calculated and compared between staining methods.
Main Results:
- A median of 0.17 mast cells/100 hepatocytes was found using May-Grünwald-Giemsa stain.
- A median of 0.47 mast cells/100 hepatocytes was found using Toluidine Blue stain.
- Toluidine Blue identified a higher median number of mast cells compared to May-Grünwald-Giemsa.
Conclusions:
- Toluidine Blue stain is more sensitive for detecting hepatic mast cells in normal canine livers than May-Grünwald-Giemsa.
- Both staining methods indicated that mast cells constitute less than 1% of cells in normal canine liver samples.
- These findings provide a critical reference for interpreting canine liver cytology.
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-Grünwald-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-Grünwald-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.
