Overview

• Rarely seen in circulating blood, hence presence is significant.
• Promote inflammatory and allergic (immediate and delayed hypersensitivity) reactions by release of mediators such as histamine, heparin, serotonin and hyaluronic acid.
• Difficult to distinguish from circulating mast cells in mast cell tumors Skin: mastocytoma. Distinguish by segmented nucleus (basophils) versus ovoid to round nucleus (mast cells).

Sampling

Tests

Methodologies

• Manual hemocytometer - accuracy +/- 20-25%.
• Electronic counting systems - accuracy +/- 3-5% ( intralaboratory precision) +/- 10-15% (interlaboratory precision).
• QBC-V hematology system.

Availability

• Widely available at commercial laboratories.
• May be performed in practice.

Validity

Sensitivity

• Sensitive.

Specificity

• Non-specific.

Predictive value

• Useful if used in conjunction with differential white blood cell counts.

Technician (extrinsic) limitations

• Some experience is required for accurate identification of leukocytes.

Result Data

Further Reading

Publications

Refereed papers

• Recent references from VetMedResource and PubMed.

Other sources of information

• Cowell R L, Tyler R D & Meinkoth J H (1999) Diagnostic Cytology and Hematology of the Dog and Cat. 2nd edn. Mosby, USA.
• Duncan J R, Prasse K W & Mahaffy E A (1994) Veterinary Laboratory Medicine Clinical Pathology. 3rd edn. Iowa University Press, USA.
• Jain N C (1993) Essentials of Veterinary Hematology. Lea & Febiger, USA.