Role of nuclear morphometry in diagnosis of salivary gland neoplasms

Fine needle aspiration cytology is an important diagnostic tool in salivary gland cytopathology. However, cytology of salivary gland neoplasms shows diversity with morphological overlap, heterogeneity and subjective variability, posing diagnostic challenge. Nuclear cytomorphometric image analysis turns the subjective criteria into quantitative parameters, which may aid not only in differentiating between benign and malignant tumours but also can aid in categorising challenging cases with morphological overlap.

A retrospective analysis of Papanicolaou stained fine needle aspirate smears from 50 patients with salivary gland neoplasms, with available follow-up histopathology, was performed. The aspirates were categorised in to three neoplastic categories of Milan system for reporting salivary gland cytology (MSRSGC) that is benign neoplasm, salivary gland neoplasm with uncertain malignant potential, and malignant. The smears were subjected to cytomorphometric image analysis using Image Pro Software (version 10). Each nucleus was analysed for 13 parameters including aspect ratio, intensity, diameter, perimeter, roundness, area, Feret diameter, circularity, radii, Fournier description and chromatin texture characteristics such as margination, heterogeneity and clumpiness. The data obtained was compared through relevant statistical methods.

The comparative morphometric data obtained for parameters using ANOVA, for the three categories showed statistically significant P values (<0.001). The post hoc test (Games-Howel) test also showed significant P values (<.001).

Cytomorphometric image analysis is an important tool in diagnosis of salivary gland neoplasms and can improve the diagnostic accuracy for better treatment and improved prognosis. However, more studies with larger sample size may be needed in future for further affirming its role.