Abnormal uterine bleeding [AUB] is one of the most common complaints of women of all age groups in the gynecology outpatient department. It was redefined by Federation International de’Gynecologie et d'Obstetrique (FIGO) in 2009 as ‘Bleeding from the uterine corpus that is abnormal in volume, regularity and/or timing that has been present for the majority of the last 6 months1. It includes menorrhagia, metrorrhagia, menometrorrhagia, polymenorrhagia, polymenorrhea, continuous vaginal bleeding and intermenstrual bleeding2.

FIGO has designed the PALM-COEIN (Polyp, Adenomyosis, Leiomyoma, Malignancy and Hyperplasia, Coagulopathy, Ovulatory Disorders, Endometrial Disorders, Iatrogenic Causes, and Not Classified) classification system for causes of AUB in the reproductive years. Common pathologies related to endometrium that can be detected histologically in AUB include hormonal imbalance patterns (disordered proliferative endometrium, non-secretory endometrium with stromal and glandular breakdown, luteal phase defect and pill effect), atrophic endometrium, endometritis, endometrial polyp,

Abnormal uterine bleeding (AUB) is a clinical entity of grave importance and may have a significant impact on physical, social, emotional and material quality of life of the affected female 3. It interferes with her routine activities because of the unpredictable nature and excessive bleeding and can also lead to anaemia. It is reported to occur in 9-14% of women worldwide between menarche and menopause^4.

The various patterns of AUB can be evaluated by histopathology which is the Gold standard for the clinical diagnosis of endometrial pathologies and their management. Our study was done to determine the histopathological patterns of endometrium among women of different age groups presenting with AUB.

All specimens of endometrial curettage, biopsy and hysterectomy received for histopathological examination in the department of pathology GMC, Haldwani from January 2020 to September 2021, have been included in the study. Specimens were fixed in 10% formalin. In hysterectomy specimens, sections were taken from all the representative areas. The tissue pieces were processed routinely and stained with hematoxylin and eosin. The clinical details were noted along with histopathological findings. Endometrial thickness was determined by ultrasonography.

Inclusion Criteria: All females presenting with abnormal uterine bleeding.

Exclusion Criteria: Bleeding other than endometrial causes, Pregnancy, Age group < 20years

A total of 103 cases of abnormal uterine bleeding (AUB) were included in this study; 58 (56.31%) were of dilatation and curettage (D&C) and 45 (43.69%) of total abdominal hysterectomy (TAH).

Cases were divided into 5 age groups. The maximum frequency of AUB was observed in 40-49 years age spectrum (61.17%) followed by 50 – 59 years (17.48%) while the minimum was seen in 20-29 years (1.94%) (Figure 1).

Menorrhagia (28.16%) was the most common complaint of patients in our study followed by postmenopausal bleeding (25.24%). An age specific comparative analysis of the clinical presentations revealed that menorrhagia was most common in 40- 49 years age group (21 cases) and Post-menopausal bleeding in 50- 59 years (17 cases) (Figure 2).

Figure 1 Figure 2

The most common endometrial patterns seen on histopathology were the normal physiological phases of menstrual cycle - proliferative (29.12%) and secretory endometrium (26.21%) respectively. Disordered proliferative endometrium was the most common pathology seen (23.31%). Minimum cases reported were of tuberculous endometritis and Atypical Hyperplasia / Endometrioid Intraepithelial Neoplasm (0.97% each). 5 cases were Nondiagnostic (Table 1).

Age specific comparative analysis showed that the incidence of endometrial hyperplasia and malignancy were more common in perimenopausal and postmenopausal age groups. Tubercular endometritis was seen in younger age group(< 30 years) (Table 1)

Maximum number of cases reported (50.49%) had an endometrial thickness of 4 – 9 mm, out of which 28 were of proliferative phase. 31 cases (30.10%) were those with an endometrial thickness ranging from 9 – 15 mm, of which 25 were in secretory phase. 7 cases (6.79%) were reported with an endometrial thickness of >20mm of which 2 cases were of endometrial carcinoma (Table 2)

Abnormal uterine bleeding (AUB) is a challenging issue encountered in women of different age groups in Gynecological OPD. Histopathological evaluation of endometrium with radiological correlation plays a pivotal role in the diagnosis and management. The present study includes a total of 103 cases presenting with complaints of Abnormal uterine bleeding, out of which 58 (56.31%) samples were of Dilatation and curettage (D and C) and 45 (43.69%) of total abdominal hysterectomy (TAH) .

In our study, majority of the cases (63; 61.16%) belonged to the age group of 40-49 years. A similar observation was made by Doraiswami et al. 5 and Damle et al. 6. This may be explained by the fact that these patients are in their perimenopausal phase during which cycles become short and anovulatory due to a decline in the number of ovarian follicles and high estradiol levels. Contrary to ours, a study by Varun M et al. 7 shows maximum number of cases in the age group of 35-39 years.

Maximum number of our cases (30; 29.12%) were reported as proliferative phase endometrium similar to the study by Sur D et al. 8 and Varun N et al. 7. The shift towards urbanization in Uttarakhand has led to an increase in hormone dependent pathologies. The bleeding in proliferative phase may be due to anovulatory cycles. A significant number of our cases showed a disordered proliferative phase pattern which lies at one end of the spectrum of proliferative lesions. The other end includes carcinoma with intervening stages of hyperplasia. An earlier stage of presentation due to increased health awareness and accessibility to health care facilities could explain the high incidence of proliferative phase endometrium in our study. Atrophic endometrium was seen predominantly in the 40- 49 years age group. The lower incidence of endometrial carcinoma in this study may be due to the practice of early childbearing and multiparity as well as early intervention. A study conducted by Jetley S et al 9 and Chhatrasal C et al 10 showed a maximum number of cases in the secretory phase endometrium. 5 of our cases were reported as nondiagnostic due to various reasons including less than adequate biopsy, only hemorrhagic material with broken glands and autolysed samples.

In our study, Menorrhagia was the most common complaint (29; 28.16%) similar to findings of Behera et al 11 and Swami et al 12 which is well explained by anovulatory cycles.

In contrast to our study, polymenorrhea and metrorrhagia were the most common bleeding patterns according to Abid M et al 13 and Golecha N et al 14.

A maximum number of our cases belonged to the proliferative phase with an endometrial thickness of 4- 9 mm followed by the secretory phase with an endometrial thickness of 9-15mm. This observation is similar to the findings of Sur D et al 8 and Khanna et al 15. Contrary to ours, a study done by Pai AH et al ^{16 s}howed maximum cases with simple hyperplasia without atypia with endometrial thickness of 11-20mm. In the study by Pillai et al 17, the mean endometrial thickness was 7.45 mm in the proliferative phase and 12.45 mm in the secretory phase which is consistent with our findings. Pillai et al 17, and Aslam et al 18 noted abnormal endometrial histopathology in endometrial thickness greater than 15 mm which correlates with our findings. In their as well as our study, no major endometrial pathology was detected in endometrial thickness <15 mm.

The endometrial thickness is highly variable and there is no clear definition of an abnormal endometrial thickness as different studies specify different values. In our study, it ranges from 2.3 mm to 24.4 mm. In menstruating women, the endometrial thickness increases gradually and measures 10- 12 mm by the day of ovulation and increases further up to 16 mm by the secretory phase. All the cases of hyperplasia and endometrial carcinoma in the present study were having endometrial thickness of >15 mm similar to Pillai et al 17 and Aslam et al ¹⁸.

Thus, our study suggest that endometrial thickness may be normal up to 15 mm depending on the phase of endometrium and findings above this value should raise a red flag sign for further evaluation.

Abnormal Uterine Bleeding (AUB) is one of the most commonly encountered gynecological problems and may be the only presenting complaint in patients with malignant or pre-malignant endometrial lesions.

Our study demonstrates the spectrum of endometrial lesions in patients presenting with AUB in the Kumaon region. Pre malignant and malignant lesions occur mainly after the fourth decade , thus females above this age group must be thoroughly evaluated including regular follow ups.

The present study concludes a significant association between endometrial thickness by Ultrasonography and histopathology in AUB cases. A cutoff value of 15mm or more is observed in cases of hyperplasia and endometrial carcinoma. Therefore, we recommend that USG findings with endometrial thickness of 15mm or above should alarm the clinicians for meticulous assessment to rule out possibilities of endometrial carcinoma and other pre malignant entities.

A definitive diagnosis of AUB could help clinicians to plan successful management timely, thus avoiding complications and radical surgeries. Hence, our study supports the histopathology of endometrial lesions as an important tool in the diagnosis and management of AUB.

Due to COVID-19 pandemic, there was a significant decrease in the number of samples received in our department as our hospital was converted into Covid hospital.

The hormonal status of the female patients presenting with abnormal uterine bleeding could not be evaluated due to non-availability of these tests in our institute and since these tests are expensive, they are not affordable to poor patients.

Lack of availability of Immunohistochemistry and molecular study in our hospital hinders further evaluation of malignancies.