Prevalence and Risk Factors of Endometrial Carcinoma Associated with Endometrial Polyps: A Retrospective Study of 2588 Polish Patients.

Background/

Objectives

Endometrial polyps are a prevalent pathological condition within the uterine cavity. While the majority of lesions are classified as benign, histopathological examinations indicate a potential for malignant transformation occurring in 0.5-5% of cases. The present study aimed to evaluate the prevalence of endometrial carcinoma and pre-malignant histopathological findings (glandular hyperplasia without atypia and atypical glandular hyperplasia) associated with endometrial polyps and to identify pertinent risk factors among Polish women undergoing hysteroscopic polypectomy under local anesthesia.

Methods

A retrospective cohort study was conducted at the Outpatient Hysteroscopy Center of the Heliodor Swiecicki University Hospital of Gynecology and Obstetrics, affiliated with Poznan University of Medical Sciences. The study included patients treated using the GUBBINI mini-resectoscope under local anesthesia with the Hystero-Block system (Tontarra Medizintechnik GmbH, Wurmlingen, Germany) between December 2022 and July 2026. Statistical analysis of risk factors was performed using the Kruskal-Wallis H test and Fisher's exact test. Odds ratios for potential risk factors were also calculated.

Results

The study comprised 2588 patients. Endometrial carcinoma associated with endometrial polyps was identified in 16 women (0.62%). Additional histopathological findings included glandular hyperplasia in 360 patients (13.91%) and atypical hyperplasia in 35 patients (1.35%), with the remaining patients diagnosed with benign uterine polyps (84.12%). Patients with malignant and pre-malignant lesions were significantly older than those with benign polyps (p < 0.001). Regarding polyp size, patients diagnosed with glandular hyperplasia without atypia had significantly larger polyps than those with benign lesions (p < 0.001). Estimated postmenopausal status was associated with significantly higher odds of endometrial carcinoma (Odds Ratio [OR] = 6.56, 95% Confidence Interval [CI]: 2.12-20.30, p = 0.001) and atypical glandular hyperplasia (OR = 3.13, 95% CI: 1.41-6.96, p = 0.005) compared to benign polyps. Similarly, obesity increased the odds of glandular hyperplasia without atypia (OR = 1.32, 95% CI: 1.01-1.74, p = 0.045) and atypical glandular hyperplasia (OR = 3.33, 95% CI: 1.67-6.65, p < 0.001). Furthermore, hypertension was associated with higher odds of glandular hyperplasia without atypia compared to benign polyps (OR = 1.41, 95% CI: 1.02-1.97, p = 0.040). Other evaluated risk factors, including type II diabetes mellitus, infertility, abnormal uterine bleeding, breast cancer history, hypothyroidism and polyendocrine metabolic ovarian syndrome (PMOS), did not reach statistical significance (p > 0.05). This large cohort provides important data regarding the prevalence and risk factors of carcinoma associated with endometrial polyps and pre-malignant uterine lesions in Polish women.

Conclusions

Endometrial carcinoma associated with endometrial polyps is a rare entity among Polish women undergoing outpatient hysteroscopy (0.62%). Nevertheless, the primary diagnostic value of this large-scale study lies in demonstrating that despite the low prevalence of malignancy in standard "see-and-treat" outpatient settings, systematic histopathological evaluation remains an absolute diagnostic mandate, as relying solely on visual or clinical parameters is insufficient to exclude malignancy. Furthermore, identified risk factors, such as age, polyp size, estimated postmenopausal status, obesity and hypertension, serve as critical diagnostic red flags, associated with increased odds of concurrent premalignant lesions or carcinoma.