Argyrophilic Nucleolar Organizer Regions (AgNOR) Count and Subjective AgNOR Pattern Assessment (SAPA) Score: Powerful Adjuncts in the Cytological Diagnosis of Breast Neoplasms

Abstract Background: Argyrophilic nucleolar organizer region (AgNOR) staining is a rapid and cost-effective marker of cellular proliferation, useful in differentiating benign from malignant breast lesions. This study evaluated the mean AgNOR count and the subjective AgNOR pattern assessment (SAPA) score in fine needle aspiration cytology (FNAC) samples of breast neoplasms. Materials and Methods: This prospective study included 100 women with palpable breast lumps who underwent FNAC at a tertiary care teaching hospital over 2 years. Smears were stained with hematoxylin and eosin (H and E) for cytology and silver stain for AgNOR analysis. Mean AgNOR count (mAgNOR) and SAPA score were evaluated in 100 neoplastic cells per case. Histopathology was available for 61 cases for correlation. Data were analyzed using SPSS 20.0; descriptive statistics and Chi-square tests were applied, with P < 0.05 considered statistically significant. Results: Among 100 breast lesions, FNAC classified 53% as benign, 36% as malignant, and 11% as premalignant, with fibroadenoma and ductal carcinoma being the most common benign and malignant lesions, respectively. Histopathological follow-up was available for 61 cases. Mean AgNOR counts rose progressively from benign (3.62 ± 0.91) to premalignant (4.92 ± 1.52) and malignant lesions (6.79 ± 2.11; P < 0.001), paralleling histopathology. SAPA scores similarly distinguished benign (6.92 ± 1.49), premalignant (10.27 ± 1.95), and malignant lesions (12.42 ± 2.43; P < 0.001). FNAC-histopathology concordance was high, with all malignant cases confirmed and 75% of premalignant cases upgraded to malignancy. Conclusion: These findings suggest that both AgNOR count and SAPA score are reliable indicators of proliferative activity and can effectively differentiate malignant from benign breast lesions in FNAC smears.