Morphologists overestimate the nuclear-to-cytoplasmic ratio

Area of Science:

• Cytopathology
• Urologic Pathology

Background:

• The Paris System for Reporting Urinary Cytology (TPS) established nuclear-to-cytoplasmic (N:C) ratio cutoffs for risk stratification.
• Pathologists may lack training in precise N:C ratio recognition, potentially impacting diagnostic accuracy.
• A survey assessed pathologists' ability to estimate N:C ratios according to TPS standards.

Purpose of the Study:

• To evaluate the accuracy of pathologists in estimating nuclear-to-cytoplasmic (N:C) ratios based on The Paris System (TPS) criteria.
• To identify potential discrepancies in N:C ratio assessment among different professional groups within pathology.

Main Methods:

• An online survey presented ideal (line drawing) and real (cell photograph) images with N:C ratios ranging from 0.3 to 0.8.
• Participants estimated N:C ratios using predefined categories: <0.5, ≥0.5 and <0.7, and ≥0.7.
• Data from 137 participants (cytopathologists, general pathologists, cytotechnologists, residents, nonmorphologists) were analyzed for accuracy.

Main Results:

• Overall correct response rates were 70.0% for <0.5, 67.6% for ≥0.5 and <0.7, and 93.3% for ≥0.7.
• Overestimation of N:C ratios occurred in 30.0% (<0.5) and 25.0% (≥0.5 and <0.7) of responses, with >40% overestimation for ratios of 0.4 and 0.6.
• Morphologists demonstrated significantly higher accuracy than nonmorphologists (P=.030).

Conclusions:

• Morphologists tend to overestimate N:C ratios, particularly near TPS-defined cutoff values.
• The findings suggest a need for enhanced training in N:C ratio estimation to improve adherence to TPS guidelines.
• Accurate N:C ratio assessment is crucial for effective risk stratification in urinary cytology.