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Research project

Endometrial Intraepithelial Neoplasia (EIN) study

Status: ongoing

We study the accuracy of the EIN diagnosis in office-based endometrial sampling; i.e., aspiration sampling devices and hysteroscopy, and the risk of a malignancy after such diagnosis.

What we do

About our project

Aim of this project 

Several clinical problems can be related to (pre) malignancies of the endometrium. For histopathological analyses, the EIN scheme is applied, differentiating between benign, EIN, and malignant endometrial diseases. One of the major strengths of this system is its correlation to outcome data; a diagnosis of EIN imparts a 45-fold increased risk of progression to carcinoma after the first year.

All knowledge is based on retrospective analyses of tissues obtained by classical dilatation and curettage (D&C) procedures, while currently endometrial samples are obtained in an outpatient setting, retrieving much smaller samples. We study the EIN classification in current daily practice.


Postmenopausal bleeding is one of the main reasons for women to visit a gynaecologist. The Dutch national guideline for women with postmenopausal bleeding - revised in 2016 - recommends that all women should undergo a hysteroscopy after a benign office sample. This recommendation is based on minimal evidence. A hysteroscopy is invasive and uncomfortable, requires a proper setting, is time consuming, and more expensive than a wait-and-see policy. In our project we will investigate the adherence to, and efficiency of the current guideline, as well as the cost effectiveness.

Execution of the project

This is a prospective multicentre study, including all women aged 40 years and older, who visit the outpatient clinic of a participating centre with any indication for endometrial biopsy. Biopsies are examined in the traditional way (hyperplasia / malignancy) and with the EIN system. All data regarding diagnostic tests, outcome and treatment will be collected and analysed.

Impact on patient care

We might find that the current guideline for postmenopausal bleeding does not improve the diagnosis of (pre) malignancies at reasonable costs, and that sub-groups of patients do not benefit from the more extended diagnostics. If so, in the future a patient tailored approach might be offered.

Our research focus

EIN classification

The diagnosis of EIN can be summarized as a focus of clustered endometrial glands exceeding a gland to stroma ratio of 1:1, which have altered cytology from the background endometrium, and which comprise a sufficient volume of 1 mm. Given that in an office setting only a very small specimen is obtained, it is questionable if EIN could be diagnosed at all. It is also unclear if the diagnosis of EIN in a endometrial sample reflects a pre malignancy or a malignancy. Making this distinction is important for treatment planning. An inter-observer study will give more information on this matter.

Funds & Grants

This study is supported by the involved departments of the participating hospitals


Collaboration within Erasmus MC

  • Departments of Gynaecologic Oncology
  • Department of Pathology

Collaboration outside of Erasmus MC

  • Albert Schweitzer Hospital, Dordrecht
  • Bravis hospital, Bergen op Zoom
  • Fransiscus Vlietland group, Rotterdam

Our team

Any questions?

Please contact our office if you have any questions or comments.

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