Atypical glandular cells in Papanicolaou test: Which is more important in the detection of malignancy, architectural or nuclear features?

Objective Atypical glandular cells (AGCs) in Pap (Papanicolaou) smears are uncommon but may represent various benign and malignant lesions. The aim of this study was to evaluate the AGC incidence in Pap smears, analyse the relationship between AGC and malignancy, and reveal the importance of architectural and nuclear features observed cytologically in malignancies. Methods Patients diagnosed with AGC on the basis of cervicovaginal cytology between May 2011 and July 2018 were included in this study. All slides were retrospectively reviewed and subclassified according to the Bethesda 2001 classification system. The cytomorphological features observed in the smears were recorded. Cytohistological correlations were evaluated, and the significant clinicopathological findings for malignancy were determined. Results Of 87 536 Pap smears, 195 (0.22%) had AGC results and 156 had tissue follow-up. Among the 156 smears with AGC, 80 (51.3%) were diagnosed as AGC-NOS (atypical glandular cells, not otherwise specified) and 76 (48.7%) as AGC-FN (atypical glandular cells, favour neoplastic). Follow-up biopsies revealed benign pathologies in 49 cases (31.4%) and malignant pathologies in 107 (68.6%). The rate of malignancy observed in AGC-FN cases (89.5%) was higher than the rate of malignancy in AGC-NOS cases (48.8%). Among the cytomorphological features, nuclear irregularity, presence of macronucleoli, feathering, loss of polarity, papillary pattern, and three-dimensional formation were found to be significant indicators of malignancy. Conclusion As AGC in Pap smear was associated with a clinically significant diagnosis in 68.6% of the cases in our study, we suggest that all patients with AGC should undergo further clinical assessment.