Background: Endometrial intraepithelial neoplasia/atypical endometrial hyperplasia (EIN/AEH) carries a substantial risk of concurrent endometrial carcinoma at hysterectomy. Sentinel lymph node (SLN) mapping requires cervical injection into an intact uterus, so the decision to map must be made before uterine pathology is known. A strategy that defers that decision to intraoperative frozen section therefore does not choose between mapping and no mapping; it forecloses mapping altogether. We evaluated the technical feasibility and diagnostic yield of SLN mapping performed without frozen section in patients with preoperative EIN/AEH and estimated how much of the nodal disease identified might not have been detected under a frozen-section-guided pathway. Methods: In this retrospective single-center study, 86 patients with a preoperative diagnosis of EIN/AEH underwent hysterectomy, bilateral salpingo-oophorectomy, and SLN mapping with methylene blue between November 2021 and May 2026. No patient underwent intraoperative frozen section, and all SLNs underwent ultrastaging. Patients were grouped by final histopathology, and carcinomas were staged according to FIGO 2023. A counterfactual analysis applied the Mayo intraoperative triage criteria to the final uterine pathology and considered two mechanisms separately: patients who would not have undergone nodal assessment at all, and patients who would have undergone lymphadenectomy but whose disease volume might not have been detected by conventional nodal pathology. Results: Final pathology showed persistent EIN/AEH in 37 patients (43.0%) and endometrial carcinoma in 49 (57.0%). Patients upgraded to carcinoma were older (60.3 ± 9.5 vs. 53.1 ± 10.4 years, p = 0.001), more often postmenopausal (87.8% vs. 54.1%, p = 0.001), and had greater endometrial thickness (18.6 ± 8.7 vs. 13.5 ± 5.4 mm, p = 0.004). At least one SLN was retrieved in 82 of 86 patients (95.3%) and bilaterally in 76 (88.4%); bilateral detection did not differ significantly between groups (94.6% vs. 83.7%, p = 0.177). SLNs lay in the obturator region in 62.2% of hemipelves and in the external iliac region in 26.3%, together accounting for 88.5%. Nodal involvement was identified in 11 patients (12.8% of the cohort; 22.4% of carcinomas): isolated tumor cells in two, micrometastasis in six, and macrometastasis in three. Among the patients who underwent additional non-sentinel nodal assessment, no metastatic non-SLN was identified in the presence of negative SLNs; no reference standard was applied to the remaining SLN-negative patients, so a false-negative rate cannot be estimated. No patient with EIN/AEH-only pathology had nodal involvement. Under simulated frozen-section triage, 2 of the 11 node-positive patients (18.2%) would not have undergone nodal assessment at all; a further 6 had low-volume disease that might not have been identified by conventional nodal pathology. Taken together, up to 8 of 11 (72.7%), and up to 6 of the 9 with micro- or macrometastasis (66.7%), might have remained undetected under the specified hypothetical pathway. Conclusions: SLN mapping performed before hysterectomy and without intraoperative frozen section was technically feasible with methylene blue alone and identified occult nodal disease, a substantial part of which might not have been detected under a frozen-section-guided pathway. These findings establish feasibility and diagnostic yield only: the study has no comparison group and supports no conclusion about survival, morbidity, or cost-effectiveness. Because 43.0% of patients had EIN/AEH-only pathology, mapping should form part of individualized preoperative counseling rather than be applied universally.

Background/Objectives: Rare histologic subtypes of cervical cancer are uncommon and may be misclassified during initial diagnosis. Their recognition depends on subtype-directed immunohistochemistry, which excludes metastatic mimics, and on high-risk HPV (hrHPV) testing, which establishes HPV status. Published series rarely report how the diagnosis was reached. We therefore documented the full diagnostic work-up, together with treatment and outcomes, in a consecutive single-center series. Methods: This was a retrospective, single-center case series (January 2020–January 2025). Rare tumors were defined per the 2020 WHO Classification as subtypes other than squamous cell carcinoma and usual-type adenocarcinoma. Immunohistochemistry was used to confirm lineage and exclude mimics. hrHPV DNA testing and p16 immunohistochemistry were performed where tissue permitted. A tumor was called HPV-associated only when diffuse block-type p16 positivity accompanied hrHPV DNA; HPV DNA alone was not accepted as evidence of an HPV-driven tumor. Results: Ten patients were included (median age 53 years). There were two signet-ring cell adenocarcinomas, two small cell neuroendocrine carcinomas (SCNECC), two serous adenocarcinomas, and one each of sarcomatoid carcinoma, clear cell carcinoma, granulocytic sarcoma, and poorly differentiated adenosquamous (glassy cell) carcinoma. hrHPV DNA was detected in six of the seven tumors tested. Three of these six were p16-negative: one serous, the clear cell, and the glassy cell carcinoma. Because diffuse block-type p16 expression is a validated surrogate marker of transcriptionally active hrHPV, we classified these three as HPV-independent. This matches the known biology of these histotypes. Lymphovascular space invasion was present in eight patients (80%). Over a median follow-up of 10.5 months, four patients developed distant metastases and three died. Conclusions: Accurate diagnosis of rare cervical tumors requires subtype-directed immunohistochemistry to exclude mimics and hrHPV testing interpreted together with p16; HPV DNA positivity alone does not establish HPV-association. Given the small, heterogeneous series, outcome data are descriptive and hypothesis-generating. We propose a diagnostic algorithm and immunohistochemical framework and advocate centralized review and prospective registries.

Objective. Endometrial intraepithelial neoplasia (EIN) is a premalignant lesion associated with a substantial risk of concurrent endometrial carcinoma. This study aimed to evaluate whether preoperative endometrial thickness measured by transvaginal ultrasonography could predict concurrent endometrial carcinoma in patients diagnosed with EIN. Methods. This retrospective study included 102 patients diagnosed with EIN on endometrial sampling who subsequently underwent hysterectomy. Demographic and clinical data and preoperative endometrial thickness were collected, and final histopathology after hysterectomy was recorded. Receiver operating characteristic (ROC) curve analysis and multivariable logistic regression were performed. Results. The median endometrial thickness was 13 mm (range 4–45), and most patients were postmenopausal (68.6%). Final pathology revealed endometrial carcinoma in 50 patients (49.0%) and persistent EIN in 52 (51.0%). Endometrial thickness significantly predicted concurrent carcinoma (AUC 0.679, 95% CI 0.575–0.784; p = 0.002), with an optimal cut-off of 14.5 mm (sensitivity 58.0%, specificity 75.0%). Carcinoma was found in 69.0% of patients with thickness ≥ 14.5 mm versus 35.0% below this value (p < 0.001). On multivariable analysis, endometrial thickness (OR 1.15 per mm; 95% CI 1.05–1.24; p = 0.001) and age (OR 1.11; 95% CI 1.02–1.19; p = 0.007) were independently associated with concurrent carcinoma. Conclusions. Preoperative endometrial thickness is independently associated with concurrent endometrial carcinoma in patients diagnosed with EIN. A thickness of 14.5 mm or greater may indicate a higher risk of malignancy; however, given its moderate diagnostic accuracy, it should complement rather than replace a comprehensive preoperative assessment.