Gastric-type Endocervical Adenocarcinoma: Comprehensive Cytopathological Analysis and Comparison With Usual-type Endocervical Adenocarcinoma

Background/Aim: Gastric-type endocervical adenocarcinoma (GEA) is a rare but distinct histological type of gynecological malignancy. This study aimed to conduct a comprehensive analysis of the cytological features of GEA. Patients and Methods: We reviewed 18 cytological samples obtained from 14 patients with GEA. All cytology slides were prepared using conventional smear and liquid-based preparations. We examined the differences between the cytological features of GEA and usual-type endocervical adenocarcinoma (UEA). Results: The cytological samples of GEA exhibited flat, honeycomb-like cellular sheets (p=0.035), vesicular nuclei (p=0.037) with prominent nucleoli (p=0.037), and vacuolated cytoplasm (p<0.001) more frequently than those of UEA, irrespective of the sampling site and preparation method. UEA showed three-dimensional cellular clusters (p<0.001), peripheral nuclear feathering (p<0.001), and nuclear hyperchromasia (p=0.014) more frequently than GEA. Conclusion: GEA can be identified cytologically based on the presence of flat, honeycomb-like sheets of tumor cells possessing vesicular nuclei, prominent nucleoli, and abundant vacuolated cytoplasm.