[1260] Evaluation of Histological Types of Endometrial Carcinomas: Experiences from Endometrial Biopsies of 358 Consultation Cases

Jian-Jun Wei, Pacita Keh. Northwestern University, Chicago, IL

Background: Uterine serous carcinoma (USC, type II), accounts for 10% of all endometrial cancers, and is more aggressive than the endometrioid cancer (EMC, type I). Since USC has a higher propensity for lymphovascular invasion, extrauterine spread than EMC, meticulous staging is important. For this reason, accurate diagnosis of the tumor type for endometrial carcinomas in endometrial biopsies/curetting specimen is particularly valuable for surgical management. While consultation of endometrial neoplasm biopsies is a standard protocol in gyn-oncology practice, the value and importance of agreeing upon the type of endometrial carcinoma deserve further investigation.
Design: A total of 358 biopsies of endometrial carcinomas were reviewed from the last three years of consultation records. The cases were from 49 hospitals, medical centers and private groups. Patients' ages ranged from 19 to 86 years old. For those cases with no agreement upon the type of endometrial carcinomas between the original diagnosis and consultation, one or more relevant immunomarkers were examined, including b-Catenin, CEA, cytokeratin, ER, PR, P16, P53, Vimentin, and WT1. Most cases with revised diagnoses for tumor types were further correlated with hysterectomy specimen.
Results: Among the 358 endometrial carcinomas, original diagnoses of type I carcinoma accounted for 91% of cases (327/358) and type II carcinoma for 9% (31 cases). A total of 41 cases (11.5%) were questioned for tumor type based on histology alone. All 41 cases were further examined by immunohistochemistry. Of the 41 cases, 36 cases (10.1%) were reclassified based on histology and immunohistochemistry (10 cases were changed from USC to EMC; 18 cases from EMC to USC; 8 cases resulted in various other outcomes (clear cell vs Secretory or squamous differentiation; Carcinosarcoma vs EMC with dedifferentiated; endometrial EMC vs cervical usual type) and 5 cases (1.4%) remained undetermined.
Conclusions: Overall, 10% of endometrial carcinoma cases from our consultation were reclassified. Interpretation of type I and II endometrial carcinomas remains a common problem in general practice. Common errors include: 1) lack of awareness of the importance of tumor types; 2) bias towards a single histologic feature, 3) sole reliance upon p53; 4) lack of examination of relevant immunomarkers. In addition, there are a small proportion of endometrial carcinomas that have a low grade 'endometrioid' appearance, aggressive growth behavior and inconclusive immunostains. Further clinical and molecular studies may help define the nature of these tumors.
Category: Gynecologic & Obstetrics

Wednesday, March 21, 2012 1:00 PM

Poster Session VI # 197, Wednesday Afternoon


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