Diagnosis
Diagnosis of EIN lesions is of clinical importance because of the increased risk of coexisting (39% of women with EIN will be diagnosed with carcinoma within one year) or future (the long term endometrial cancer risk is 45 times greater for a woman with EIN compared to one with only a benign endometrial histology) endometrial cancer. Diagnostic terminology is that used by pathologists, physicians who diagnose human disease by examination of histologic preparations of excised tissues. Critical distinctions in EIN diagnosis are separation from benign conditions such as benign endometrial hyperplasia (a field effect in endometrial tissue caused by excessive stimulation by the hormone estrogen), and cancer.
The spectrum of disease which must be distinguished from EIN (Table II) includes benign endometrial hyperplasia and carcinoma:
Table II: Disease classes that need to be distinguished from EIN.
| Disease Class |
Endometrial Topography |
Functional Category |
Treatment |
|---|---|---|---|
| Benign endometrial hyperplasia |
Diffuse | Hormone (estrogen) Effect |
Hormonal therapy |
| EIN, Endometrial Intraepithelial Neoplasia |
Focal progressing to diffuse (clonal) |
Precancer | Hormonal or surgical |
| Endometrial Adenocarcinoma |
Focal progressing to diffuse (clonal) |
Cancer | Surgical stage-based |
EIN may be diagnosed by a trained pathologist by examination of tissue sections of the endometrium. All of the following diagnostic criteria must be met in a single area of one tissue fragment to make the diagnosis (Table III).
Table III: EIN diagnosis.
| EIN Criterion | Comments | |
|---|---|---|
| 1 | Architecture | Gland area exceeds that of stroma, usually in a localized region. |
| 2 | Cytological Alterations |
Cytology differs between architecturally crowded focus and background. |
| 3 | Size greater than 1mm | Maximum linear dimension should exceed 1mm. Smaller lesions have unknown natural history. |
| 4 | Exclude mimics | Basalis, normal secretory, polyps, repair, lower uterine segment, cystic atrophy, tangential sections, menstrual collapse, disruption artifact, etc. |
| 5 | Exclude Cancer | Carcinoma should be diagnosed if: glands are mazelike and rambling, there are solid areas of epithelial growth, or there are significant bridges or cribriform areas. |
Read more about this topic: Endometrial Intraepithelial Neoplasia