Clinicopathological and ultrasound assessment of endometrial hyperplasia in perimenopausal women.

BACKGROUND: Endometrial hyperplasia (EH) is a heterogeneous proliferative endometrial disorder frequently encountered during perimenopause, characterized by variable architectural complexity, cytological atypia and biological behavior. AIM: This study aimed to evaluate the clinical, ultrasonographic (US), histopathological (HP) and immunohistochemical (IHC) features of EH in perimenopausal women and to assess the associations between these parameters. PATIENTS, MATERIALS AND METHODS: This multicenter observational study included 103 perimenopausal women with histopathologically confirmed EH, evaluated between 2020 and 2025. Patients were stratified into two age-defined subgroups: Group A (40-45 years, n=49) and Group B (46-51 years, n=54). All patients underwent standardized US evaluation according to International Endometrial Tumor Analysis (IETA) terminology, followed by HP examination. IHC analysis was performed in selected representative cases. RESULTS: Abnormal uterine bleeding (AUB) was the predominant clinical presentation in both groups. Significant differences between subgroups were observed for previous endometrial biopsy, uterine dimensions, adenomyosis prevalence and endometrial thickness. Group B showed significantly greater uterine dimensions, higher prevalence of adenomyosis and increased mean endometrial thickness. HP evaluation demonstrated a heterogeneous spectrum of architectural, cytological, stromal and vascular alterations. Significant age-related differences were identified for atypical EH∕endometrial intraepithelial neoplasia (EIN), nuclear atypia, increased mitotic activity, vascular proliferation and abnormal vascular morphology, all being more frequent in Group B. IHC assessment further demonstrated substantial biological heterogeneity across EH lesions. CONCLUSIONS: Perimenopausal EH represents a heterogeneous spectrum of proliferative endometrial lesions with progressive clinicopathological complexity during the perimenopausal transition. Integrated US, HP and IHC assessment provides a comprehensive framework for lesion characterization, particularly in morphologically complex cases.