Endometrial cancer is the most common gynecological malignancy and its incidence has shown a steady rise over recent decades. Early and accurate diagnosis is crucial, as timely detection significantly improves treatment outcomes and overall prognosis.1 Women presenting with abnormal uterine bleeding (AUB), particularly postmenopausal bleeding, represent a high-risk group in whom prompt evaluation of the endometrium is essential.2,3 TVS is widely available, non-invasive, cost-effective, and generally well tolerated, making it suitable as an initial diagnostic tool in routine clinical practice.An increased endometrial thickness on TVS raises suspicion for endometrial pathology, including hyperplasia and malignancy, and typically warrants further invasive investigations such as endometrial biopsy and/or hysteroscopy for definitive diagnosis.4 To stratify the risk of endometrial cancer, various ET cut-off values, usually ranging between ≥3 mm and ≥5 mm, have been proposed in the literature. These thresholds aim to maximize sensitivity so that malignancy is not missed; however, this approach inevitably leads to reduced specificity.5 Consequently, a significant proportion of women with benign conditions are subjected to unnecessary invasive procedures, increasing patient anxiety, healthcare costs, and procedural-related morbidity.6To improve diagnostic performance, several studies have explored the use of subjective pattern recognition during ultrasound examination. This approach involves assessment of endometrial morphology, echogenicity, integrity of the endomyometrial junction, and vascular patterns using color or power Doppler imaging. Although incorporation of these features has been shown to enhance the sensitivity of ultrasound in detecting endometrial cancer, the specificity remains suboptimal.7 As a result, the challenge of distinguishing benign from malignant endometrial pathology using ultrasound alone persists.Moreover, TVS is not always reliable in visualizing and accurately measuring the endometrium. Previous studies have reported that adequate assessment of the endometrium is not possible in approximately 20–38% of women undergoing TVS. In such cases, endometrial thickness may be overestimated, further reducing the specificity of the investigation. Factors contributing to poor visualization include obesity, uterine position, and coexisting uterine pathologies. Common structural abnormalities such as uterine fibroids and adenomyosis can distort the uterine cavity and myometrial architecture, making accurate delineation of the endometrium difficult on TVS8. Additionally, an axial or markedly flexed uterus may result in an unfavorable angle of insonation, leading to erroneous ET measurements. Emerging evidence suggests that alternative imaging techniques, such as transrectal ultrasound, may provide improved visualization of the endometrium in selected cases, particularly in women with an axial uterus.9 However, whether such secondary imaging modalities significantly enhance diagnostic accuracy compared with TVS alone in women presenting with AUB requires further investigation. AIM The aim of this study is to evaluate the significance of endometrial thickness measured by transvaginal ultrasonography in women presenting with abnormal uterine bleeding and to assess its correlation with histopathological findings.

This prospective observational study was conducted in the Department of Obstetrics and Gynaecology at SPMC and associated hospitals Bikaner from June 2024 to may 2025. A total of 80 women presenting with abnormal uterine bleeding were included in the study. All participants underwent a detailed clinical evaluation followed by transvaginal ultrasonography for assessment of endometrial thickness using a high-frequency transvaginal probe. Endometrial thickness was measured in the sagittal plane at the point of maximum thickness, from one endometrial–myometrial interface to the other. Women with increased endometrial thickness or persistent abnormal uterine bleeding subsequently underwent endometrial sampling by aspiration or dilatation and curettage, and the obtained tissue was sent for histopathological examination, which was considered the gold standard for diagnosis. The ultrasonographic findings were correlated with histopathological results to assess the diagnostic significance of endometrial thickness. Women aged 18 years and above presenting with abnormal uterine bleeding in the form of menorrhagia, metrorrhagia, polymenorrhea, menometrorrhagia, or postmenopausal bleeding were included in the study. Both premenopausal and postmenopausal women who consented to undergo transvaginal ultrasonography and endometrial sampling were considered eligible for inclusion. Pregnant women and those with pregnancy-related bleeding were excluded from the study. Patients with known bleeding disorders, women receiving anticoagulant therapy, and those who had used hormonal medications within the preceding three months were also excluded. In addition, women with acute pelvic inflammatory disease, known cervical malignancy, or those unwilling to participate were not included in the study.

Table 1: Demographic variables of studied participants Variable Number Percentage Age group (years) <30 6 7.5 30-39 14 17.5 40-49 38 47.5 ≥50 22 27.5 Parity Nulliparous 5 6.3 P1 6 7.5 P2 18 22.5 P3 23 28.7 P4 and above 28 35.0 The majority of women in the study belonged to the 40–49-year age group (47.5%), followed by those aged ≥50 years (27.5%), indicating that abnormal uterine bleeding was most common in the perimenopausal age group. Most participants were multiparous, with parity of P3 or more seen in a substantial proportion, while nulliparous women constituted only a small percentage of the study population. Table 2: Distribution of patients according to presenting complaints complaints Number Percentage Menorrhagia 18 22.5 Menometrorrhagia 26 32.5 Polymenorrhea 15 18.7 Metrorrhagia 7 8.8 Postmenopausal bleeding 14 17.5 The most common presenting complaint among the study participants was menometrorrhagia, reported by 26 women (32.5%), followed by menorrhagia in 18 women (22.5%). Polymenorrhea was seen in 15 women (18.7%), while postmenopausal bleeding accounted for 14 cases (17.5%). Metrorrhagia was the least common complaint, observed in 7 women (8.8%). Table 3: Distribution of patients according to ultrasonography findings USG finding Number Percentage Fibroid uterus 32 40 Adenomyosis 6 7.5 Endometrial hyperplasia 5 6.3 Endometrial polyp 4 5 No obvious abnormality 33 41.2 On ultrasonographic evaluation, the most common finding was no obvious abnormality, seen in 41.2% of women, followed closely by fibroid uterus in 40% of cases. Adenomyosis, endometrial hyperplasia, and endometrial polyps were less frequent findings, accounting for a small proportion of patients with abnormal uterine bleeding. Table 4: Distribution of endometrial thickness on transvaginal ultrasonography Endometrial thickness (mm) Number Percentage ≤4 4 5 4.1–8 50 62.5 8.1–12 14 17.5 12.1–16 8 10 >16 4 5.0 Most participants had endometrial thickness between 4.1–8 mm (62.5%), followed by 8.1–12 mm (17.5%) and 12.1–16 mm (10%). Thickness ≤4 mm and >16 mm were less common, seen in 5% of cases each. Table 5: Endometrial patterns on histopathological examination Endometrial pattern Number Percentage Proliferative phase 50 62.5 Secretory phase 13 16.3 Pseudodecidual reaction 2 2.5 Endometrial hyperplasia 8 10 Adenocarcinoma 3 3.7 Atrophic endometrium 2 2.5 Unsatisfactory tissue 2 2.5 The most common endometrial pattern observed was the proliferative phase in 50 cases (62.5%), followed by the secretory phase in 13 cases (16.3%). Other findings included endometrial hyperplasia (10%), adenocarcinoma (3.7%), pseudodecidual reaction, atrophic endometrium, and unsatisfactory tissue, each seen in 2–2.5% of cases. Table 6: Histopathological findings according to endometrial thickness (mm) HPE finding ≤4 mm (n=4) 4.1–8 mm (n=50) 8.1–12 mm (n=14) 12.1–16 mm (n=8) >16 mm (n=4) Proliferative 0 36 10 2 2 Secretory 1 11 1 0 0 Pseudodecidual 0 2 0 0 0 Endometrial hyperplasia 0 1 2 4 1 Adenocarcinoma 0 0 1 2 0 Atrophic endometrium 2 0 0 0 0 Unsatisfactory tissue 1 0 0 0 1 Histopathological examination showed that proliferative endometrium was most common in the 4.1–8 mm group, while secretory endometrium appeared mainly in ≤4 mm and 4.1–8 mm groups. Endometrial hyperplasia and adenocarcinoma were seen mostly in thicker endometrium, whereas atrophic and unsatisfactory tissue were rare. Table 7: Association between histopathological findings and mean endometrial thickness HPE finding Mean ET (mm) SD Proliferative phase 7.1 2.0 Secretory phase 6.4 1.2 Pseudodecidual reaction 5.6 0.8 Endometrial hyperplasia 13.6 2.4 Adenocarcinoma 15.2 1.8 Atrophic endometrium 4.1 0.3 The mean endometrial thickness was highest in adenocarcinoma (15.2 ± 1.8 mm) and endometrial hyperplasia (13.6 ± 2.4 mm), while proliferative and secretory phases had moderate thickness (7.1 ± 2.0 mm and 6.4 ± 1.2 mm, respectively). Pseudodecidual reaction and atrophic endometrium showed the lowest thickness, 5.6 ± 0.8 mm and 4.1 ± 0.3 mm, respectively.

The age distribution of the study participants showed that the majority of women belonged to the 40–49-year age group, accounting for nearly half of the study population, followed by women aged 50 years and above. Younger women below 30 years constituted a small proportion of the cases. This indicates that abnormal uterine bleeding was more commonly observed in perimenopausal and postmenopausal age groups. Regarding parity, most women were multiparous, with the highest proportion seen among women with parity four and above. Parity three and parity two women also formed a substantial part of the study population. Nulliparous women represented only a small fraction, suggesting a higher prevalence of abnormal uterine bleeding among multiparous women in this study. Mishra P et al10 In the present study 242 participants were included with mean age as 44.73 ± 3.67 years. Most of the females were in the age group 40-45 years (61.15%) and were multiparous (82.63%). The most common presenting complaint among the study participants was menometorrhagia, reported by nearly one-third of women, indicating irregular and heavy bleeding as a frequent reason for seeking medical attention. Menorrhagia was the next most common symptom, affecting about one-fifth of the participants. Polymenorrhea was observed in a considerable proportion, reflecting frequent menstrual cycles as a manifestation of abnormal uterine bleeding. A smaller number of women presented with metrorrhagia, characterized by bleeding between menstrual periods. Postmenopausal bleeding constituted a significant group and is clinically important due to its association with endometrial pathology. Among the 80 women evaluated, transvaginal ultrasonography revealed that fibroid uterus was the most common finding, observed in 32 women, accounting for 40% of cases. No obvious abnormality on ultrasound was noted in 33 women (41.2%), indicating that a substantial proportion of patients with abnormal uterine bleeding had no gross structural pathology on imaging. Adenomyosis was identified in 6 women (7.5%), suggesting a smaller but clinically relevant contribution to abnormal bleeding patterns. Endometrial hyperplasia was detected on ultrasonography in 5 women (6.3%), highlighting the importance of further evaluation in cases with suspected endometrial thickening. Endometrial polyps were seen in 4 women (5%), representing another focal intrauterine cause of bleeding. The distribution of endometrial thickness among the study participants showed that the majority, 50 cases (62.5%), had a thickness ranging from 4.1 to 8 mm. A smaller proportion, 14 cases (17.5%), had thickness between 8.1 and 12 mm, while 8 cases (10%) fell in the range of 12.1 to 16 mm. Only 4 participants (5%) had a thin endometrium measuring ≤4 mm, and an equal number had a thick endometrium of >16 mm. This indicates that normal to mildly increased endometrial thickness was the most common finding in the study group. Very thin or excessively thick endometrium was relatively uncommon. The endometrial pattern among study participants showed that the majority, 50 cases (62.5%), were in the proliferative phase, indicating normal cyclical endometrial development. The secretory phase was observed in 13 cases (16.3%), reflecting the luteal phase of the cycle. Endometrial hyperplasia was found in 8 cases (10%), suggesting abnormal proliferation of the endometrium. Adenocarcinoma was diagnosed in 3 cases (3.7%), representing the malignant endometrial changes. Pseudodecidual reaction, atrophic endometrium, and unsatisfactory tissue were each noted in 2 cases (2.5%), indicating less common or inconclusive findings. Histopathological examination of endometrial samples revealed that proliferative endometrium was the predominant pattern, seen mainly in the 4.1–8 mm group (36 cases), with smaller numbers in the 8.1–12 mm, 12.1–16 mm, and >16 mm groups. Secretory endometrium was observed in 1 case of ≤4 mm and 11 cases of 4.1–8 mm, with minimal representation in the 8.1–12 mm group. Pseudodecidual reaction was limited to 2 cases in the 4.1–8 mm group. Endometrial hyperplasia was more common in thicker endometrium, occurring in 1 case of 4.1–8 mm, 2 cases of 8.1–12 mm, 4 cases of 12.1–16 mm, and 1 case of >16 mm. Adenocarcinoma was detected in 1 case of 8.1–12 mm and 2 cases of 12.1–16 mm. Rare findings included atrophic endometrium (2 cases in ≤4 mm) and unsatisfactory tissue (1 case in ≤4 mm), indicating that pathological changes were associated with increased endometrial thickness. The mean endometrial thickness varied according to the histopathological pattern. Adenocarcinoma had the highest mean thickness of 15.2 ± 1.8 mm, followed closely by endometrial hyperplasia at 13.6 ± 2.4 mm, indicating that pathological thickening was associated with these conditions. The proliferative phase showed a mean thickness of 7.1 ± 2.0 mm, while the secretory phase had a slightly lower mean of 6.4 ± 1.2 mm, representing normal cyclical endometrial changes. Pseudodecidual reaction exhibited a mean thickness of 5.6 ± 0.8 mm, reflecting a mild increase. Atrophic endometrium had the lowest mean thickness of 4.1 ± 0.3 mm, consistent with thinning. Overall, these findings demonstrate a correlation between increasing endometrial thickness and the likelihood of hyperplastic or malignant changes. Poonia, L,11 Menometrorrhagia (28%) was the chief complaint. Proliferative endometrium (66%) was the most common endometrial pattern, followed by secretory endometrium (16%), endometrial hyperplasia (7%), adenocarcinoma (3%), atrophic endometrium (2%), and pseudodecidual reaction (1%). Out of the total cases, in 5 (5%) cases, no histopathological pattern was observed because of inadequate sample. After applying analysis of variance, the association between histopathological findings and mean ET was found to be statistically significant (P = 0.00). When ET was >12 mm, endometrial hyperplasia and adenocarcinoma were observed in six and one cases, respectively.

The study concludes that abnormal uterine bleeding was most commonly observed in women of perimenopausal and postmenopausal age, particularly among multiparous women. Menometrorrhagia was the predominant presenting symptom, while fibroid uterus was the most frequent ultrasonographic finding, though a substantial proportion of women had no obvious structural abnormality. Endometrial thickness correlated strongly with histopathological changes, with proliferative and secretory patterns being common in normal endometrium, and endometrial hyperplasia and adenocarcinoma predominantly seen when thickness exceeded 12 mm. Overall, transvaginal ultrasonography combined with endometrial histopathology proved to be an effective, reliable method for evaluating abnormal uterine bleeding and identifying women at risk of hyperplastic or malignant endometrial changes.

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