A morphometric approach in breast cytology--geometrical descriptors in the differentiation between benign and malignant lesions.

This study focuses on the analysis of geometric descriptors that can be applied in breast cytology, and their correlation with the qualitative features, with the aim to underline the differences between the benign and malignant cell profile. The morphometric investigation was performed on smears obtained by fine needle aspiration, 10 cases (group 1) diagnosed as benign and 10 cases (group 2) as malignant. For group 2, the malignancy was histopathologically confirmed on the surgical resection specimen. The sequence of automated operation, previously reported by us, permitted the extraction of the following geometrical descriptors: cytoplasmic area, nuclear area, nucleo-cytoplasmic ratio, equivalent diameter and form factor. We analyzed the differences between the benign and malignant morphometric features, and the correlation between the malignant morphometric features and cytological, respectively histological grading. Statistically significant difference in cytoplasmic areas, nuclear areas, value of nucleo-cytoplasmic ratio and equivalent diameter was noted between group I and II. For the form factor, we did not register statistically significant differences. For group 2, the correlation between the morphometric features and cytological grading revealed that the nuclear area is the most valuable descriptor, due to the significant differences between the three successive grades of cytological severity, followed by the cytoplasmic area and equivalent diameter, their numerical values presenting significant differences between cytological grade 1 and 3, and 2 and 3, respectively. The statistical analysis between the morphometric features and histological grading showed that nuclear area and equivalent diameter are the most viable indicators, due to the significant differences present between the three successive grades of pathologic severity, followed by cytoplasmic area (significant differences only for grade 2 versus 3) and for nucleo-cytoplasmic ratio (significant differences only for grade 1 versus 2). The form factor does not provide information that could be correlated with the cytological or histological grading. The defined morphometric features enable the characterization of benign and malignant cells and provide objective criteria that could support a differentiation of benign from the malignant pathology in the cytological diagnosis.