[1225] Endometrial Intraepithelial Neoplasia and Secretory Change: Diagnostic Features and Underlying Mechanisms

Carlos Parra-Herran, George L Mutter. Brigham and Women's Hospital - Harvard Medical School, Boston, MA

Background: Endometrial Intraepithelial Neoplasia (EIN) and subdiagnostic areas of gland crowding (GC) are difficult to interpret in the presence of secretory differentiation. We determined how often EIN and GC lesions with secretory differentiation are associated with background changes referable to circulating progestins.
Design: We identified all sequential cases over a 69 month interval in which the diagnostic report contained the descriptor “secretory” and either “EIN” or ”gland crowding”. 36 EIN and 24 GC cases had slides available. Morphologic features in lesional and background endometrium, and presence within a polyp, were recorded by two observers blinded to prior report diagnoses. All observations were analyzed separately for EIN and GC groups.
Results: EIN patients studied averaged 45.2 years of age, and those with GC 46.6 years, both significantly younger (p<0.01) than historical average (53 years) of all patients diagnosed with EIN at our institution.

Table 1: Comparison of secretory differentiation within lesion (EIN or GC) and background glands.
 TOTAL (%)21.079.0100.0 
 TOTAL (%)14.785.3100.0 

Table 1 shows that in 76% of EIN cases secretory differentiation was intralesional and not significantly (p=0.159) associated with circulating progestins (secretory background endometrium). 74% of GC lesions were secretory, and positively associated with a secretory background (p=0.012). Polyps tended to be more frequent within the GC (29%) than EIN (19%) series (p=0.272), but both groups were less frequent (p=0.039, p<0.001, respectively) than the 43.4% polyp rate seen for all patients with EIN at our hospital. 15% of GC lesions were located within an EMP (p=0.091), compared to only 4% of EIN lesions (p=0.366).
Conclusions: Secretory EIN and EIN in a secretory background are rare lesions which occur in younger patients, and are less likely to occur in polyps than their non-secretory counterparts.
Secretory differentiation within EIN does not require actively circulating progestins, as indicated by the histology of the background endometrium.br]Secretory differentiation in GC lesions parallels that of the background endometrium, supporting a hormonal cause.
Accurate examination and dating of the background endometrium may be useful in the diagnosis of EIN with secretory differentiation and in the classification of sub-diagnostic (GC) lesions.
Category: Gynecologic & Obstetrics

Monday, March 19, 2012 9:30 AM

Poster Session I Stowell-Orbison/Surgical Pathology/Autopsy Awards Poster Session # 173, Monday Morning


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