The uterus has two major components: the myometrium and the endometrium. The endometrium, which is composed of glands embedded in cellular stoma is a hormonally responsive tissue undergoing cyclic proliferation, differentiation and shedding during the menstrual cycle under influence of ovarian steroids [1, 2] This dynamic tissue plays a crucial role in etiology of various gyneological conditions, which include abnormal uterine bleeding (AUB) which is now becoming one the major concern of women of all age groups. AUB is defined as bleeding that deviates in frequency, duration, or amount from normal menstrual patterns. It is a distressing condition that is common and affects a person's physical, emotional, and social well-being. It comprises approximately 20–30% of outpatient gynecologic consultations among reproductive-age women [3-5]. The prevalence of AUB ranges from 9% to 30% and tends to increase with age, and higher incidence is reported in perimenopausal women, especially in those who experience anovulatory cycles [3, 6]. The prevalence of AUB in India is around 17.9% [7]. Dysfunctional uterine bleeding (DUB) is an important cause of AUB, which occurs without any identifiable organic pathology in perimenopausal females. Menorrhagia tends to occur in 10–30% of menstruating women at any given time and in up to 50% during perimenopause [6]. In postmenopausal women, the occurrence of AUB raises greater concern due to the higher risk of malignancy. Thus, timely and accurate diagnosis is important to exclude serious underlying pathology such as endometrial carcinoma. The incidence of which has been found in 10% of cases on histopathological examination [8]. Therefore, histopathological evaluation of the endometrium becomes essential in identifying the cause of AUB, especially in women aged 40 years and above or those who are postmenopausal [9, 10]. Endometrial sampling remains a cornerstone in the diagnostic workup, with dilatation and curettage (D&C) used previously as a standard technique. However, its invasiveness, requirement for general anesthesia, and associated risks such as uterine perforation and infection have led to the development of safer, minimally invasive sampling methods [11–15]. Identifying the spectrum of endometrial lesions ranging from normal cyclical changes to hyperplasia, polyps, and malignancy helps guide appropriate medical or surgical management required in these cases. Accurate diagnosis not only enables timely intervention and reduces unnecessary procedures but also aids in preventing long-term complications. Given the wide range of histopathological findings associated with AUB, this study aims to analyze the spectrum of endometrial lesions in patients presenting with abnormal uterine bleeding at a tertiary care hospital and correlate them with age groups, helping to optimize patient care.

This was a descriptive cross-sectional study conducted in the Department of Pathology at Dr. Balasaheb Vikhe Patil Rural Medical College, Pravara Rural Hospital, a tertiary care teaching hospital located in a rural setting in Loni, Maharashtra, India. Institutional Ethical approval was obtained for the study. The duration of the study was from October 2019 to November 2021. The study included female patients with gynecological conditions requiring endometrial sampling via biopsy or hysterectomy. Reporting to our hospital.

Inclusion Criteria

All endometrial samples (both biopsy and hysterectomy specimens) received in the Department of Pathology during the study period were included.

Exclusion Criteria

Specimens with insufficient tissue for histopathological evaluation were excluded.

Sample Size: A total of approximately 500 cases were analyzed.

Methodology: Endometrial specimens were received from the Department of Obstetrics and Gynecology following procedures such as dilatation and curettage (D&C) or hysterectomy. All samples were transported in 10% neutral buffered formalin. Upon receipt, specimens were grossly examined, properly labeled, and fixed in formalin for 24 hours. For hysterectomy specimens, sections were taken from the endometrium, myometrium (from the fundus, body, and cervix), and cervix (including ectocervix, endocervix, and transformation zone from both lips). A minimum of three sections were taken from any grossly visible lesion. Endometrial biopsy specimens were weighed and fully submitted. Tissue Processing of samples was performed using an automatic tissue processor as per standard protocol.

Sectioning and Staining: Tissue blocks were sectioned at 3–4 µm thickness using a rotary microtome. Sections were floated on a 70% alcohol bath to prevent wrinkling and transferred to a 46–50°C water bath. The sections were mounted on albumin-coated slides, dried in a hot air oven, deparaffinized with xylene, and stained using the standard Hematoxylin and Eosin (H&E) protocol. Final stained slides showed nuclei in blue and cytoplasm in varying shades of pink.

Data Collection and Analysis: Clinical and pathological data were collected from patient case records. All data were compiled using Microsoft Excel. Statistical analyses were performed using IBM SPSS Statistics version 20.0 (SPSS Inc., Chicago, IL, USA) and OpenEpi version 2.3.1. Descriptive statistics, including mean, range, standard deviation, and percentage, were used. The Chi-square test was applied to categorical variables, and Student’s t-test was used for continuous variables. A p-value of <0.05 was considered statistically significant.

A total of n=500 samples of endometrial biopsy and hysterectomy coming to the department of pathology, Dr. Balasaheb Vikhe Patil Rural Medical College, Loni, were included in the study. Table 1 shows the age-wise distribution of the cases included in the study. The majority of the study population (62%) belonged to the 40–50 years age group, indicating a predominance of perimenopausal women. This was followed by women under 40 years, comprising 19% of the total, and those aged between 50–60 years, making up 11%. The least represented group was women aged 60 years and above, accounting for only 8% of the cases. The mean age of the cohort in years was 44.9+11.2 years.

Figure 2 depicts the various clinical presentations observed in the study population. The most frequent symptom reported was pain in the abdomen, seen in 30.2% of the cases, followed closely by per vaginal bleeding (27%) and menorrhagia (20.2%). These results are indicative of common gynecological complaints, resulting in additional assessment of endometrial pathology. Less common presentations included abnormal uterine bleeding (8.4%), dysmenorrhea (6.4%), and mass per vagina (1.6%). Rare symptoms such as excessive weight loss (0.6%), menopause-related complaints (0.8%), and postpartum hemorrhage (0.4%) were also noted. The 'others' category (4.4%) encompassed various non-specific or less frequently reported complaints. This data shows that an abnormal bleeding pattern is commonly prevalent. Atypical clinical presentation, including a number of other indicators, requires endometrial examination, thereby implying a broader assessment of symptoms.

Figure 1: History of Symptoms among the Study Population

Table 2 presents the distribution of clinical symptoms across different age groups in the cohort. A critical analysis of the table shows that the clinical presentation varies depending on age. The age group 40–50 years had the highest frequency of most symptoms, especially pain in abdomen (81 cases), per vaginal bleeding (84 cases), and menorrhagia (80 cases). These symptoms are frequently reported in perimenopausal women because of hormonal fluctuations or structural anomalies.  In the age group <40 years, there were striking symptoms including pain in the abdomen (31 cases) and menorrhagia (19 cases), usually associated with anovulatory cycle or hormonal imbalance. The ≥60 years group had higher frequencies of more serious or less common symptoms such as mass per vagina (5 cases) and others (8 cases), which may suggest neoplastic or postmenopausal causes that warrant detailed investigation. More importantly, menorrhagia and dysmenorrhoea were rarely reported in women ≥60 years, consistent with the postmenopausal state. Rare symptoms like excessive weight loss and postpartum hemorrhage were observed only in a few cases. Overall, the results show that statistically significant association. This reveals that age is an important factor influencing the type of gynecological symptoms, and it can guide clinicians in tailoring diagnostic approaches across age groups.

*Significant

Table 3 shows the clinical diagnosis of the 500 women studied.  The most common diagnosis in the cases was uterine/cervical fibroid, 39.4% (197 cases). Fibroids are common benign tumors of reproductive age women and the primary cause of abnormal uterine bleeding and pelvic discomfort. Dysfunctional uterine bleeding / abnormal uterine bleeding was the second most frequently diagnosed condition. It was observed in 37.2% (186 cases). This reflects a high trend of bleeding disorders among women, especially at the perimenopausal age. Uterovaginal prolapse was noted in 8% (25 cases) and is commonly associated with multiparity and muscle weakness of the pelvic floor in aged women. Ovarian tumors/masses/cysts were seen in 3.2% (16 cases) and adenomyosis in 3.6% (18 cases). All are associated with pain and menstrual irregularities. Other rare but important conditions included endometrial carcinoma (0.6%), carcinoma cervix (1.4%), and hydatidiform mole (0.6%), thus underscoring the need to carry out histopathological analysis in detecting potentially malignant or premalignant lesions.

In the present study, out of 500 cases, hysterectomy specimens had a maximum of n=397(79%), while the remaining 103 (21%) were endometrial biopsies. The maximum number of cases of hysterectomy specimens, it is worth noting that vast numbers of gynecological conditions were detected among women that were severe and required surgical management of the uterus, such as fibroids, prolapse, or persistent abnormal uterine bleeding unresponsive to conservative measures. In contrast, endometrial biopsies are mainly used for diagnostic assessment, especially in patients with abnormal uterine bleeding or suspected endometrial pathology, especially in perimenopausal or postmenopausal women.

The description of the association between age group and type of specimen is given in Table 4. A critical analysis of the table shows that the majority of hysterectomy specimens were observed in the 40–50 years age group (261 cases, 65.7% of hysterectomies), followed by the <40 and 50–60 years age groups. Endometrial biopsies were more frequently performed in the 40–50 years group (49 cases) and the <40 years group (32 cases), although the decision was solely based on the clinical symptoms and need for conservative diagnostic methods before a surgical approach. A statistically significant association was found between the age group and type of specimen (p < 0.001), implying that the type of specimen collected varies significantly with age.

*Significant

Table 5 projects the association between the type of specimen and histopathological diagnosis for endometrial biopsy and hysterectomy. The table showed that the proliferative phase of the endometrium was found in both biopsies as well as hysterectomy specimens. The secretory phase was distributed in 29 hysterectomy specimens and 30 biopsies. Atrophic endometrium and cystic atrophy were also common in hysterectomy samples, while cystic hyperplasia and endometrial hyperplasia, both types, were observed. Endometrial carcinoma was very rare (one biopsy specimen and five hysterectomy specimens).

*Significant

Table 6 summarizes the 494 non-neoplastic endometrial lesions (98.8% of specimens). The most common were the proliferative-phase endometrium (35.8%), atrophic endometrium (11.8%), and secretory-phase endometrium (7.8 %). Simple hyperplasia contributed 8.2%, while complex hyperplasia with and without atypia contributed 3.2% and 4.2%, respectively. Adenomyosis and cystic glandular hyperplasia accounted for 4.6 % of all the cases. Other rare entities were disordered phases (5.8%), endometrial polyps (3.4%), cystic atrophy (3.8%), and endometritis (2%). Decidual, gestational, and pill endometria accounted for <4% of all cases.

  Among 6 malignant lesions, n=3 (50%) cases are endometroid carcinoma, n=1(16.6%) case of adenosquamous carcinoma, n=1(16.6%) case of mucinous adenocarcinoma, and 1(16.6%) case of undifferentiated adenocarcinoma is observed in this study, as given in Table 7. These results emphasize the relative rarity of malignant endometrial neoplasms in this cohort and the importance of careful histopathological assessment in differentiating multiple carcinoma subtypes for proper clinical management.

The current study was done in 500 women for histopathological analysis of endometrial specimens (both neoplastic and non-neoplastic), conducted over two years at the Department of Pathology in a tertiary care hospital. The results of this study showed a statistically significant association (χ² = 17.02, p < 0.001) between the age group and type of specimen. The most frequently received specimens were hysterectomy samples in 79% of cases, which were predominantly from the age group 41 – 50 years, n=261 (81.8%), followed by the age group 31 – 40, n=131 (80.5%). In our study, the mean age was 44.9 ± 11.2 years, and the age group with the highest incidence of patients was the 41–50 years group, ranging from 19–85 years. Studies show that the average age can differ, where: The mean age reported by A Sobande et al. [16] was 51.29 ± 12.86 years, Günakan et al. [17] 70.53 years, and Deeba et al. [18] calculated the mean age as 61.6 ± 6.17 years. The difference in the mean age among studies may be attributed to variations in population makeup, the number of participants, or the availability of healthcare services. Similar findings were reported by Tiwana et al. [19], who frequently received samples from perimenopausal women. In their study, they found endometrium was in the proliferative phase in 35.22% of cases and atrophic endometrium in 25.8% of cases. The findings of this study also align with several other Indian and international studies, which include the study by Singh et al. [20], who found that proliferative endometrium was the most common histological pattern. Naeem et al. [21] in a similar study found proliferative endometrium in 29%, endometrial hyperplasia in 24.8%, chronic endometritis in 16.8%, and atrophic endometrium in 12.6% of cases.

In the current study, from the non-neoplastic lesions, we found proliferative endometrium was the most frequent histopathological finding (35.8%), followed by atrophic endometrium (11.8%), and simple hyperplasia (8.2%). In 7.8% of cases secretory phase endometrium was diagnosed. 179 cases of hysterectomy specimens sent showed signs of the proliferative phase, and 31 cases of biopsies also showed this stage. The high correlation between specimen type and histological findings (χ² = 68.01, p < 0.001) emphasizes the value of both hysterectomy and endometrial biopsy for the assessment of uterine pathology. Clinical presentation in our study revealed that pain in abdomen (30.2%) as the most frequently reported symptom, followed by per vaginal bleeding (27%), menorrhagia (20.2%), and abnormal uterine bleeding (8.4%). A significant association was found between age group and clinical symptoms (χ² = 214.53, p < 0.001), and the majority of symptomatic patients were in the 40–50-year age group. This is in agreement with findings by Vaidya et al. [22], who found maximum symptomatic cases in the perimenopausal age. Among malignant endometrial lesions, 1.2% of cases were neoplastic, including endometrioid adenocarcinoma (0.6%), adenosquamous carcinoma (0.2%), mucinous carcinoma (0.2%), and undifferentiated carcinoma (0.2%). These results are in agreement with the studies by Bhatta S et al. [23] and Shah S et al. [24], which observed a low incidence of malignancy in their endometrial cohorts. Endometrial sampling remains a procedure that yields valuable diagnostic information, especially on abnormal uterine bleeding and malignancies. Our study shows that proliferative and hyperplastic endometria prevail in perimenopausal women, whereas atrophic and neoplastic patterns are more common after menopause.  Overall, histopathological examination of endometrial tissue is essential for the evaluation of uterine pathology. Our findings support the clinical importance of routine histopathological evaluation, particularly in women presenting with abnormal bleeding patterns, as it helps in the early detection of pre-malignant and malignant lesions.

Within the limitations of the current study, we found that histopathological examination plays a critical role in diagnosing endometrial lesions, especially in perimenopausal women. Most specimens, particularly those from women aged 41 – 50 years, presented with a proliferative phase of the endometrium. This study found a significant association between age, clinical presentation, specimen type, and histopathological diagnosis. The diagnosis of malignant lesions is rare compared to that of non-malignant lesions. Therefore, this study highlights the importance of routine histopathological analysis of endometrial samples for early diagnosis and management of symptomatic women across different age groups.

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