Histopathological correlation of adenomyosis and leiomyoma in hysterectomy specimens as the cause of abnormal uterine bleeding in women in different age groups in the Kumaon region: A retroprospective study.

OBJECTIVE: To study adenomyosis and leiomyoma as the cause of Abnormal Uterine Bleeding AUB in hysterectomy specimens. STUDY
METHOD: A descriptive study was carried out on 184 hysterectomy specimens of patients with AUB during the period of Jan 2010 to Dec 2011. Data including age, parity, symptoms and clinical indication for hysterectomy was collected for the study. The specimens were processed routinely and stained with hematoxylin and eosin stain and examined microscopically.
RESULTS: Women in the perimenopausal age (40-50 years) accounted for the highest number of cases (44.56%) presenting with symptoms of AUB. In this age group adenomyosis was the found to be the commonest cause of AUB (46.34%).
CONCLUSION: Adenomyosis was found to be the most common cause of abnormal uterine bleeding in women of perimenopausal age group.

INTRODUCTION

Abnormal uterine bleeding (AUB) is a common cause for women in the reproductive age group to consult a doctor. AUB is also the common cause for iron deficiency anemia in our country, especially in the reproductive age group. Uterine fibroid, adenomyosis, polyp (endometrial and endocervical), endometrial hyperplasia and malignancy are the structural causes for AUB.

Hysterectomy is the definitive treatment for fibroids, adenomyosis not responding to medical treatment, hyperplasia and malignancy. Dilation and curettage is done for endometrial polyps and polypectomy for endocervical polyps that can be visualized. A number of minimally invasive surgical options for hysterectomy do exist now and are promising like endometrial ablation, thermal balloon therapy and uterine artery embolization but restricted availability and cost factor limit them from being widely used.[1] Therefore, hysterectomy still remains the widely accepted and practiced treatment of choice.

Estimates of the prevalence of adenomyosis vary widely from 5% to 70%[2] which is probably related to inconsistencies in the histopathologic criteria for diagnosis. On the contrary, leiomyomas have a high prevalence up to 70% in Caucasians and 80% in women of African ancestry.[3] They also have a wide spectrum of size and location (subendometrial, intramural, subserosal or a combination of these). Furthermore, they have widely varying rates of growth even in a single individual.

The purpose of our study was to find the prevalence of adenomyosis and leiomyoma as the cause of AUB in the Kumaon region by histopathological examination of hysterectomy specimens received in our department. The reason for selecting these two entities for our study was that adenomyosis and leiomyoma are the two most common causes for AUB. Adenomyosis presents with dysmenorrhea and AUB. The clinical presentation of leiomyoma depends on their size and location, the most common are AUB, pain and sensation of pressure. In both of them, AUB is the common presentation but unfortunately they cannot be differentiated solely on clinical ground and a histopathological examination is required.

Our hospital being the sole Government Medical College in this region caters for a large segment of population of patients in the adjoining hill, as well as border areas specially those who cannot afford the luxury of expensive private nursing homes and hospitals.

MATERIALS AND METHODS

A descriptive study was carried out in the pathology department from Jan 2010-Dec 2011. During these 2 years, 445 hysterectomy specimens were received in the pathology laboratory in the hospital. Out of these, 184 were included in the study. Inclusion criteria were women coming to outpatient department with complaint of AUB for which hysterectomy was performed. Patients in whom endometrial biopsies were inconclusive for the cause of AUB and subsequently underwent hysterectomies were also included in the study. Vaginal and abdominal hysterectomies done for complaints other than AUB and malignancies were excluded from the study.

A record of these patients was retrieved and patient's age, parity, presenting symptoms, sonography (TVS) findings and clinical indication for hysterectomy was recorded.

On gross examination, any apparent abnormality i.e., asymmetrical enlargement of the uterus, fibroid, polyp, any pinpoint/cystic areas of hemorrhage and endometrial thickening was noted. The number, size and location of the fibroid were also noted.

A minimum of two sections were taken from the cervix, two from the corpus, one from both the tubes and ovaries and an additional section was taken from the leiomyoma or any other abnormal area. Representative sections were stained with hematoxylin eosin (H and E) stain and examined microscopically.

The following criteria for the diagnosis of adenomyosis was used-

Grossly - pinpoint/small cystic areas of hemorrhage seen within the myometrium.

The microscopic criteria for the diagnosis of adenomyosis were the presence of endometrial glands and stroma in the myometrium more than one low power field away from the endomyometrial junction.

RESULTS

A total of 184 cases were included in the study. Age of the patients ranged from 30 to 70 years. The largest group (n = 82) was of perimenopausal age (41-50 years) contributing 44.56% of total cases in the study [Figure 1]. In this age group, adenomyosis was the commonest pathology 46.34% (n = 38) followed by leiomyoma 41.46% (n = 34) where as 12.19% (n = 10) showed dual pathology of adenomyosis and leiomyoma [Table 1]. In the younger age groups as well as the post-menopausal age groups adenomyosis was the leading cause of AUB. In our study, maximum cases revealed adenomyosis was the histopathological lesion (n = 94) in women who presented with abnormal uterine bleeding [Table 2].

Figure 1

Age distribution of Patients presenting with Abnormal uterine bleeding

Table 1

Distribution of patients according to the histopathological lesion

Table 2

Number of patients for each histopathological lesion

Unfortunately only a small number of patients (n = 41) had undergone TVS preoperatively. The sonographic diagnosis correlated well with the histopathological findings. Eighteen patients were given the provisional diagnosis of adenomyosis and 23 of fibroid on sonography. Out of these in 14 patients the diagnosis of adenomyosis was confirmed on histopathology whereas all the patients of fibroid uterus showed a similar histopathological diagnosis.

Out of 184 patients, 103 were preoperatively diagnosed as adenomyosis while 81 were clinically suspected to have leiomyoma as the cause of AUB. On histopathological examination only 87 of these 103 were confirmed to have adenomyosis whereas 76 patients of leiomyoma showed the same lesion [Table 3]. Therefore, the clinico-histological correlation was better for leiomyoma (93.8%) than for adenomyosis (74.7%). HMB (heavy menstrual bleeding) was the complaint in majority of the patients compared to IMB (irregular menstrual bleeding). In both the categories, bulk of the patients showed adenomyosis as the underlying histopathological lesion [Table 4]. Histological correlation of dysmenorrhea with adenomyosis was seen in 68% cases whereas in leiomyoma the correlation with pain and pressure symptoms was 76.92% in our study. Dual pathology was seen in 7% cases of dysmenorrhea while 3.8% cases showed pain and pressure symptoms [Table 5].

Table 3

Correlation of histopathological diagnosis with the clinical diagnosis

Table 4

Correlation of histopathological lesions with the type of bleeding in abnormal uterine bleeding

Table 5

Correlation of histopathological lesion with the presenting symptoms

DISCUSSION

The investigation and management of AUB among women has been hampered both by confusing and inconsistently applied nomenclature and by the lack of standardized methods for the investigation and categorization of various potential etiologies. These deficiencies hampered the ability of the investigators to study homogenous populations of patients experiencing AUB, and made it difficult to compare studies performed by different investigators or research groups. To develop a nomenclature and classification system was made more complex by the fact that a variety of potential causes may coexist in a given individual. Therefore to tackle his problem, the International Federation of Gynecology and Obstetrics (FIGO) formulated a new system of classification, which included contributions from an international group of clinician-investigators from 6 continents and over 17 countries. This group agreed that the term AUB should not be restricted to just menstrual bleeding that was abnormally heavy but also include bleeding that was abnormal in timing.

It was unanimously agreed that the term “dysfunctional uterine bleeding (DUB), which was previously used as a diagnosis when there is no systemic or locally definable structural cause for bleeding, should be discarded. Women who fit this description generally have one or a combination of coagulopathy, disorder of ovulation or primary endometrial disorder. Another term which was replaced was “menorrhagia”. It was renamed heavy menstrual bleeding (HMB) which is cyclical bleeding in excess of 80 ml per month.[4]

Evaluation of patients with abnormal uterine bleeding is achieved with a combination of history, physical examination, laboratory evaluation, USG and endometrial sampling. In a study by Shergill, heavy menstrual flow was found to be the most common presenting complaint (66%) in patients undergoing hysterectomy.[5] Sixty percent of these patients developed anemia. It is usually associated with benign pathologies and rarely with malignancies. Hysterectomy is the traditional surgical treatment of HMB. If a patient is not responding to medical treatment, it is the only surgical option available in most hospitals in our country.

Fibroids are a common finding in women with AUB. The abnormal bleeding in fibroids is due to increased size of uterine cavity thereby increasing the surface area of the endometrium, hyperestrogenemia causing endometrial hyperplasia, vascular alterations of the endometrium and obstructive effect of fibroid on uterine vasculature leading to endometrial venule ectasia which causes proximal congestion in the myometrium and endometrium.[1] Majority of women with uterine fibroid associated AUB are treated by hysterectomy.[67]

Adenomyosis is another common condition detected in hysterectomy specimens. It is characterized by the presence of endometrial glands and stroma within the myometrium. Patients are typically pre or perimenopausal women who present with abnormal bleeding. Diagnosis of adenomyosis on clinical findings alone is usually difficult. Imaging plays an important role in the evaluation of myometrial lesions and the common diagnostic modalities available in the outpatient clinic are transabdominal sonography (TAS) and transvaginal sonography (TVS). The following criteria is used for the diagnosis of adenomyosis in TVS-

Asymmetrical myometrial thickening

Heterogenous area within the myometrium

Hyperechoic region surrounded by hypoechoic area

No discrete myometrial mass

If mass present poorly defined margins

Contour of uterus unaltered

Myometrial cyst

Myometrial cyst has been cited as the most sensitive and specific feature for the diagnosis of adenomyosis[8]

Though MRI is helpful in diagnosing adenomyosis, women have a limited access to it. Reason being that is not available in most of the medical centers and even if it is the cost factor limits its utility.

In our study, 44.56% (n = 82) of the patients with AUB belonged to the 41-50 years age group. Adenomyosis was the most common cause for AUB with a frequency of 46.34% (n = 38). This is in contrast to the study done by Sajjad, et al., Sarfraz, et al., Tahira, et al. and Khawja, et al.[9101112] In all these studies leiomyoma has been reported as the commonest pathological lesion in women with AUB. The reason for this discrepancy could be that adenomyosis being asymptomatic is usually not clinically diagnosed. It may be missed on histopathology as it may not be microscopically observed if limited tissue sections are taken, which is usually the case if there is no clinical suspicion. Therefore this lesion tends to be under diagnosed in most studies. Fibroids on the other hand are usually detected on ultrasound. Gynecologists also for some reason usually are more tuned clinically to suspect fibroids as the cause of AUB rather than adenomyosis. Therefore due to strong clinical suspicion they are more thoroughly investigated for this pathology. Adenomyosis still remains a histopathological finding by chance in uterine tissue sections examined for other clinically suspected pathology.

CONCLUSION

In our study, adenomyosis was found to be the most common histopathological finding in hysterectomy specimens of women with AUB with a peak incidence in the perimenopausal age group (41-50 years) in this region. Transvaginal sonography does help in differentiating between leiomyomas and adenomyosis. Despite this adenomyosis still remains a clinical challenge. Nevertheless, the possibility of this lesion has to be kept in mind by both the clinician, as well as the pathologist in women with AUB.