Histomorphological Patterns of Endometrial Hyperplasia

Introduction

Endometrium is continuously under the influence of hormones and keeps on changing throughout the lifespan of women with complexities of periodic proliferation, differentiation, breakdown, and regeneration.¹ Menstruation is a normal physiological process of shedding of endometrium, which is associated with uterine bleeding that occurs at monthly intervals from menarche to menopause.²

Endometrial hyperplasia is a pathological condition characterized by irregular morphological alterations, whereby abnormal proliferation of endometrial glands result in an increase in gland to stroma ratio when compared to normal proliferative endometrium.^3,4 Majority of women with endometrial hyperplasia will present clinically with abnormal uterine bleeding and is a precursor lesion for the development of endometrial carcinoma. It is more evident in peri-menopausal and post-menopausal age groups.⁵ Most endometrial hyperplasia develop in a background of chronic estrogenic stimulation of the endometrium, occurring secondary to number of possible conditions.⁶

The classification of endometrial hyperplasia has undergone a number of changes over the years. In the recent past, the most widely used system divided the endometrial hyperplasia into four categories: simple hyperplasia without atypia, complex hyperplasia without atypia, simple atypical hyperplasia, and complex atypical hyperplasia. The current World Health Organization (WHO) classification recommends collapsing the four categories into two major categories based on nuclear atypia: Non-atypical hyperplasia and atypical hyperplasia, which differs in appearance and propensity to progress to carcinoma.⁷

Histopathological examination of endometrial sample is used for the diagnosis of majority of abnormal uterine bleeding. Endometrial biopsy and curettage are the important sampling methods, which aid in diagnosis and further management.⁸ The present analysis was done to understand the histopathological pattern of endometrial hyperplasia and to correlate them with clinical diagnosis.

Methodology

Data for the study were archived from histopathology records of the Pathology Department. All the lesions with histological diagnosis of endometrial hyperplasia irrespective of benign or malignant tumors over a period of 1 year were retrieved and included for the study. Information related to age, presenting clinical features, and diagnosis all were noted from the accompanying laboratory request forms. The data were tabulated and analyzed. Histological typing of endometrial hyperplasia was done depending on the new criteria used in the WHO classification.⁹

The samples of endometrial tissues were fixed in 10% formalin, processed using automated Histokinette, and 3-4 µ thick paraffin sections were made and stained with hematoxylin and eosin stain (H and E) and studied under light microscopy.

All the endometrial tissues with a microscopic diagnosis of hyperplasia were included for the study, irrespective of age and clinical features.

Inadequate specimen, menstrual endometrium, and endometrial tissue from hysterectomy specimen were excluded from this study.

Results

The present study included 40 samples (n = 40) of endometrial hyperplasia diagnosed by histopathological examination on endometrial tissue. All of these samples were obtained by endometrial curettage.

The age of the patients ranged from 21-70 years. Maximum number of patients (n = 16) were in the age group 41-50 years (40%) followed by the age group of 31-40 years (27.5%). Six (6; patients 15%) each were in the age group of 51-60 years and 21-30 years. Only one patient was encountered in the age group of 61-70 years.

The most common clinical diagnosis (Tables 1 and 2) was abnormal uterine bleeding (45%) followed by endometrial hyperplasia (17.5%). The clinical diagnosis was not available in the request forms in 2 (5%) cases. Correlating the clinical diagnosis with age group, it was found that majority of the patients (45%) who presented with abnormal uterine bleeding were mainly in the age group of 41-50 years (n = 16, 40%) followed by 31-40 years (27.5). Post-menopausal bleeding (n = 6) was common in 4th-5th decade (15%). Clinical diagnosis of endometrial hyperplasia (n = 7) was made in all the age groups and ranged from 21-70 years (17.5 %).

Non-atypical endometrial hyperplasia (34 cases, 85%) was the most common histological type of endometrial hyperplasia encountered in endometrial biopsies (Table 3). Atypical endometrial hyperplasia was seen in only 6 cases (n = 6, 15%). Of the 34 cases, maximum number of patients ie, n = 15, (44.11%) with non-a typical endometrial hyperplasia were in 5th decade of life.

Atypical endometrial hyperplasia was most commonly seen in the 5th decade of life.

Discussion

Endometrial hyperplasia is common in peri-menopausal women causing symptoms of irregular or prolonged bleeding due to anovulatory cycle in majority of cases.⁹ In a study by Naheed Moghal, majority of patients (82.3%) with endometrial hyperplasia were in the age group of 41-50 years.⁹

A study by Khan et al showed that two thirds of the cases of endometrial hyperplasia were in the peri menopausal age group.¹⁰ Gargi et al carried out a study where maximum number (46.5%) of endometrial hyperplasia occurred in patients of 41-50 years age group.¹¹ These findings were concurrent with the present study, which showed highest number of endometrial hyperplasia (40%) in the 5th decade.

Gargi et al also found that 49.6% patients presented with menorrhagia,¹¹ while our study showed 85% patients with abnormal uterine bleeding.

Non-atypical hyperplasia was the common type of endometrial hyperplasia (99.2%) in the study conducted by Gargi et al,¹¹ which is similar to our findings, ie, majority (85%) of the cases were non-atypical hyperplasia.

Conclusion

Abnormal uterine bleeding in women has been one of the most common clinical presentation and problems seen in women of all age groups. Endometrial hyperplasia has been one of the major causes of dysfunctional uterine bleeding; hence, timely diagnosis for the prevention of blood loss leading to anemia, progression, and complication is required. Histopathology remains the gold standard for the diagnosis of endometrial hyperplasia. Proper evaluation and histopathological typing of endometrial hyperplasia in different age group is the key for an efficient treatment.

Conflict of Interest

None.