A comprehensive analysis of abnormal uterine bleeding in perimenopausal women: A synthesis of etiology, diagnostic correlations, and PALM-COEIN classification

Background: Abnormal uterine bleeding (AUB) is a common gynecological concern among perimenopausal women, affecting 10-30% according to various studies. Hormonal fluctuations during the menopausal transition frequently lead to anovulation, endometrial dysfunction, and diverse structural or non-structural causes. The FIGO PALM-COEIN classification offers a standardized framework to categorize AUB into structural causes—polyps, adenomyosis, leiomyoma, malignancy/hyperplasia—and non-structural causes such as coagulopathy, ovulatory dysfunction, endometrial disorders, iatrogenic factors, and unclassified types. In this study, structural causes predominated, particularly leiomyoma, adenomyosis, and endometrial abnormalities. Accurate diagnosis is essential since perimenopausal AUB may mask pre-malignant or malignant conditions, especially when endometrial thickness (ET) exceeds 7-8 mm. Aim and Objectives: To determine the proportion of structural and non-structural causes of AUB in perimenopausal women using the FIGO PALM-COEIN classification. And to correlate clinical bleeding patterns with corresponding ultrasonographic findings, endometrial thuickness, histopathology of endometrium. Methods: This prospective observational study was conducted to determine the etiological distribution and diagnostic correlations of abnormal uterine bleeding (AUB) among perimenopausal women. A total of 32 participants, aged 40-50 years, presenting with complaints of heavy, irregular, frequent, or intermenstrual bleeding were enrolled from the outpatient department of a tertiary care teaching hospital over a three-month study period. Results: In the present 32-patient cohort, the predominant age group was 40-50 years. Heavy menstrual bleeding (HMB/menorrhagia) was the most common presentation. Structural causes formed the majority of diagnoses: ? Leiomyoma (AUB-L) was the most frequent PALM category. ? Adenomyosis (AUB-A) and endometrial polyps also contributed significantly. ? Hyperplasia-related findings were identified in biopsy specimens, with proliferative and disordered proliferative endometrium being the most common. Ultrasonography revealed fibroid uterus and adenomyosis as the leading abnormalities. Endometrial thickness most commonly ranged between 6-9 mm, while ET ?10 mm showed a stronger association with hyperplastic changes. Non-structural causes, mainly ovulatory dysfunction and endometrial disorders, contributed to a smaller proportion of cases. Anemia was present in a considerable number of women, reflecting the clinical impact of chronic heavy bleeding. Conclusion: In this 32-patient study, leiomyoma and adenomyosis emerged as the principal causes of AUB in perimenopausal women, with endometrial hyperplasia forming a key subset requiring attention. Transvaginal ultrasonography remains vital for initial assessment, while endometrial biopsy is essential when ET exceeds 7-8 mm or when imaging raises suspicion for significant pathology. The PALM-COEIN framework effectively guided structured evaluation. Early diagnosis, systematic assessment, and timely biopsy can help prevent missed malignant conditions and support individualized management in this high-risk population.