Abnormal uterine bleeding (AUB) is a characteristic complaint in clinical practice, especially in perimenopausal and postmenopausal women. It has a great influence on the quality of life, and can be a sign of underlying endometrial pathology that can be benign, such as polyps and hyperplasia, or malignant, such as endometrial carcinoma. Early and correct diagnosis is thus mandatory to provide the most timely and suitable management, minimize morbidity, and achieve better patient outcomes [1,2]. Conventionally, endometrial pathology has been assessed using a mixture of clinical tests, imaging, and histopathological techniques. Transvaginal ultrasound (TVS) has become the first-line choice of imaging because it is non-invasive, is widely available, is cost-effective, and can measure endometrial thickness and morphology. TVS is especially effective when screening patients and detecting abnormalities in the endometrium around the world. Its diagnostic value, however, may be less in the detection of focal intrauterine lesions like polyps and submucosal fibroids [3]. Hysteroscopy, however, is regarded as the gold standard in assessing the uterine cavity. It permits direct visualization of the endometrium and allows targeted biopsy of suspicious lesions. This greatly improves the accuracy of the diagnosis, especially the focal abnormalities that can be overlooked in ultrasound. Although it has its merits, hysteroscopy is invasive, requires skill, and may not be easily accessible in all healthcare facilities, particularly in resource-restricted settings [4,5]. The clear diagnosis of endometrial pathology is through histopathological examination. Thus, it is vital to compare the ability of TVS and hysteroscopy in diagnosis with that of histopathology to identify their clinical utility. A number of study works have pointed to the high accuracy of hysteroscopy, but TVS remains an important procedure to act as a first-line screening [6]. In third-world and developing nations such as Pakistan, where healthcare facilities might be minimal, cost-efficient and effective diagnostic pathways should be put in place. Excessive invasive intervention may result in patient burden and healthcare expenditures, whereas failure to adequately diagnose may postpone therapy. Therefore, it is important to determine the best mix of diagnostic modalities [7,8]. This paper will compare and contrast the diagnostic performance of transvaginal ultrasound and hysteroscopy in identifying the existence of endometrial pathologies in women with abnormal uterine Exclusion Criteria

bleeding using histopathology as the gold standard. The results of this study will be useful in informing clinicians about using the right diagnostic approaches, which will enhance patient care and resource utilization [9].

Study Design & Setting The study was a prospective comparative Study carried out at the Department of Obstetrics and Gynecology Gomal Medical College,Dera Ismail Khan from 05 January 2025 05 June 2025 over six months. Participants One hundred women aged 30-65 years with abnormal uterine bleeding were used. The patients were recruited at the outpatient and inpatient departments. Females with suspected endometrial pathology due to clinical examination were recruited. Individuals who had a pregnancy, an active pelvic infection, coagulation disorders, or who were unwilling to participate were not considered in the study. Sample Size Calculation The sample size of 100 patients was computed based on a 95% confidence interval, anticipated sensitivity of 85% of hysteroscopy, a margin of error of 7%, and prevalence of endometrial pathology based on past study. This was deemed sufficient to find statistically significant differences in the diagnostic modalities. Inclusion Criteria • Women aged 30–65 years • In patients with abnormal uterine bleeding. • Capable of giving informed consent. • Pregnancy • Pelvic inflammatory disease • Known bleeding disorders • Previously diagnosed endometrial carcinoma • Refusal to participate Diagnostic and Management Strategy Transvaginal ultrasound and subsequent hysteroscopy were conducted on all the patients. All cases had an endometrial biopsy taken and submitted to histopathology. The results of both modalities were compared to histopathological results in order to ascertain the accuracy of diagnostic results. Statistical Analysis SPSS version 25 was used to analyze the data. The quantitative variables were expressed as mean + standard deviation, whereas qualitative variables were indicated as frequencies and percentages. The sensitivity, specificity, PPV, NPV, and diagnostic accuracy were determined. The chi-square test was used, and the p-value of less than 0.05 was found to be statistically significant. Ethical Approval Statement Ethical approval for this study was obtained from the Institutional Review Board/Ethics Committee of the participating tertiary care hospital prior to commencement of the study. All procedures were conducted in accordance with institutional ethical standards and the principles of the Declaration of Helsink

A total of 100 patients were included in the study. The mean age was 44.6 ± 8.2 years. The most common presenting complaint was menorrhagia (52%), followed by metrorrhagia (28%) and postmenopausal bleeding (20%). Histopathological findings revealed endometrial hyperplasia in 30% of cases, polyps in 25%, submucosal fibroids in 15%, carcinoma in 10%, and normal endometrium in 20%. Transvaginal ultrasound detected abnormalities in 68% of patients, while hysteroscopy detected abnormalities in 85% of patients. The sensitivity and specificity of transvaginal ultrasound were 78% and 65%, respectively, whereas hysteroscopy showed higher sensitivity (92%) and specificity (85%). The positive predictive value and negative predictive value were also higher for hysteroscopy. A statistically significant difference was observed between the diagnostic accuracies of the two modalities (p < 0.05). Hysteroscopy demonstrated superior ability in identifying focal intrauterine lesions such as endometrial polyps and submucosal fibroids. However, transvaginal ultrasound proved useful as an initial screening modality for detecting global endometrial abnormalities

Table 1: Demographic and Clinical Characteristics of Patients (n = 100)

This table shows the baseline demographic and clinical profile of study participants. Most patients were aged 41–50 years, and menorrhagia was the most common presenting complaint.

Table 2: Histopathological Findings (Gold Standard) (n = 100)

This table represents histopathological diagnoses, which served as the gold standard for comparison. Endometrial hyperplasia was the most frequently observed pathology.

Table 3: Diagnostic Performance of Transvaginal Ultrasound vs Hysteroscopy

This table compares the diagnostic performance of transvaginal ultrasound and hysteroscopy. Hysteroscopy demonstrated superior sensitivity, specificity, and overall diagnostic accuracy compared to ultrasound.

Table 4: Comparison of Detection of Endometrial Pathologies by TVS and Hysteroscopy

This table shows the comparison of detection rates of different endometrial pathologies by transvaginal ultrasound and hysteroscopy against histopathological findings. Hysteroscopy demonstrated higher detection rates, particularly for focal lesions such as polyps and fibroid

The current study measured the diagnostic validity between transvaginal ultrasound (TVS) and hysteroscopy with respect to the histopathology as the gold standard of diagnosis of endometrial pathologies. Our result shows that hysteroscopy is more sensitive (92) and specific (85) than TVS (78 and 65), and the difference is statistically significant (p < 0.05). These findings are in agreement with the latest literature, which supports the use of hysteroscopy as the gold standard in measuring intrauterine pathology [10]. In a similar study, TVS sensitivity was reported in 2024 as 82.8%, and specificity was reported as 73.1% compared with hysteroscopy, which had higher sensitivity (94.9) and specificity (84.6), which is close to our results [11]. Such a similarity implies that hysteroscopy is always more accurate in its diagnosis than ultrasound, although there are slight differences. The other recent study (2025) also stated that hysteroscopy revealed more intrauterine abnormalities than TVS, which again proves its superiority [12]. Another important finding of our study was that hysteroscopy was especially helpful in detecting focal lesions like endometrial polyps and submucosal fibroids. A 2024 study confirmed this observation, in which hysteroscopy was found to be more effective in characterizing polyp size, vascularity, and malignancy potential than ultrasound [13]. On the same note, prior and recent study findings affirm that hysteroscopy is almost absolutely accurate in identifying polyps and submucosal lesions, but TVS is not sensitive to small or focal lesions [14]. On the contrary, transvaginal ultrasound is a useful screening technique because it is non-invasive, inexpensive, and easy to obtain [15]. We found that TVS identified abnormalities in 68% of cases, which is consistent with other studies that have reported moderate diagnostic performance. According to recent study, the accuracy of TVS increases substantially in the case of complex methods like saline-infusion sonography or 3D ultrasound, and the sensitivity can be up to 8692 per cent in favourable circumstances [16]. Nonetheless, these methods might not be readily accessible in poor-resource environments. The difference in the accuracy of diagnosis between TVS and hysteroscopy that we observed in our study can be explained by a number of factors. Ultrasound is operator-dependent and could be poor at differentiating between diffuse and focal lesions. Hysteroscopy, in turn, makes it possible to directly view the cavity of the uterus, which makes it possible to perform a targeted biopsy and provide immediate treatment. This has been a major strength that has been continuously pointed out in recent study due to the hysteroscopy's dual diagnostic and therapeutic nature [17]. The other significant result of our study was the prevalence of endometrial pathologies, hyperplasia, and polyps being the most frequent. The trend is in line with recent regional and international reports, which indicate the same prevalence levels of benign cases of endometrial conditions in women who present with abnormal bleeding of the uterus [18]. The fact that endometrial carcinoma was detected in 10% of the cases also highlights the significance of the proper diagnostic instrument to detect malignancy early. Although hysteroscopy is superior, its invasiveness, cost, and need for specialized expertise restrict its utilization as a first-line investigation. Thus, a gradual diagnostics strategy should be suggested. Several recent studies recommend the application of TVS as a first screening modality, and hysteroscopy as a second modality in instances of abnormal or inconclusive results. This integrative approach improves the accuracy of diagnosis with little invasive interventions. [19]. On the whole, our results are highly consistent with the literature published within the past five years, as they prove that hysteroscopy is the most reliable modality to diagnose endometrial pathologies, especially focal lesions. Nonetheless, transvaginal ultrasound remains an important first-line screening method that is non-invasive. A combination of the two modalities in a complementary form is the best and most effective practice to consider women with abnormal bleeding of the uterus [20].

Limitations

This study was carried out in one center, and the sample size was rather small (n=100), which can present a threat to external validity. There may be operator dependence in the interpretation of ultrasound. Also, more elaborate methods of imaging, such as saline infusion sonography, have not been used, which may have impacted the comparative diagnostic quality of transvaginal ultrasound.

Hysteroscopy has a greater diagnostic accuracy than transvaginal ultrasound in diagnosing endometrial pathologies, particularly focal lesions. Transvaginal ultrasound is, however, still a good screening tool. Stepwise, combined approach enhances accuracy of the diagnosis, timely management, and efficient use of resources in women who present with abnormal uterine bleeding.

ACKNOWLEDGEMENT

The authors acknowledge the support of the Gomal Medical College,Dera Ismail Khan for facilitating data collection and diagnostic procedures.

CONFLICT OF INTEREST

The authors declare no conflict of interest.

FUNDING

No external funding was received for this study.

INFORMED CONSENT

Written informed consent was obtained from all participants prior to enrollment in the study.

DATA AVAILABILITY STATEMENT

The datasets generated and/or analyzed during the current study are available from the corresponding author upon reasonable request.

DISCLAIMER

The views expressed in this article are those of the authors and do not necessarily reflect the official policy or position of the affiliated institution.

Author Contributions

Uzma Zaman contributed to the conception and design of the study, data interpretation, and critical revision of the manuscript. Nayyer Latif contributed to data collection, statistical analysis, and drafting of the manuscript. Rubina Baber contributed to study supervision, manuscript review, and final approval of the version to be published. All authors meet the ICMJE authorship criteria and approved the final manuscript

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