Mitotic Figures-Normal, Atypical, and Imposters: A Guide to Identification

Area of Science:

• Veterinary Pathology
• Histopathology
• Computational Pathology

Background:

• Mitotic figure counting (MF) is essential for tumor grading and prognosis in veterinary diagnostics.
• Current methods for MF counting are subjective, labor-intensive, and prone to interobserver variability.
• Standardization efforts in veterinary pathology are limited, particularly regarding the definition of MF and distinguishing atypical mitotic figures (AMF) from mitotic-like figures (MLF).

Purpose of the Study:

• To establish clear morphologic criteria for identifying mitotic figures (MF).
• To differentiate normal MF from atypical mitotic figures (AMF) and mitotic-like figures (MLF).
• To discuss the application of digital microscopy and computational pathology (CPATH) for accurate MF assessment.

Main Methods:

• Review and definition of morphologic characteristics for MF, AMF, and MLF.
• Discussion of digital microscopy features relevant to MF identification.
• Exploration of computational pathology (CPATH) approaches for mitotic counting.

Main Results:

• Provides standardized morphologic criteria for MF identification.
• Offers guidelines for distinguishing normal MF from AMF and MLF.
• Highlights the potential of digital tools to enhance MF assessment.

Conclusions:

• Standardized morphologic criteria will improve the consistency, reproducibility, and accuracy of mitotic counts (MC).
• Digital microscopy and CPATH methods offer promising avenues for objective MF assessment.
• Accurate MF identification is critical for reliable tumor grading and clinical decision-making in veterinary medicine.