[1155] 10-Year Retrospective Study on High-Grade Endometrial Endometrioid Adenocarcinoma (HGEEA), FIGOIII: Morphology and Immunohistochemical Characterization.

Jiyoon Yoon, Ziying Zhang. Henry Ford Hospital, Detroit, MI

Background: HGEEA is focus of attention since morphology overlaps with more aggressive non-endometrioid carcinoma (CA) (type II tumors), such as undifferentiated CA, serous CA, clear cell CA, etc. HGEEA's biologic behavior, hormone receptor expression, and proliferative activity are controversial.
Design: All endometrial CA with HGEEA diagnosis from 1999-2010 were second-reviewed. Immunostains performed on TMA blocks were p53, p16, MIB1, cytokeratin (CK), EMA, vimentin, ER/PR. Scoring system was as follows: p53 overexpression: >70% nuclear stain; ER/PR and MIB1+: >20% nuclear stain; p16 +: >75% cytoplasmic and nuclear stain; CK, EMA, and vimentin+: >20% cytoplasmic stain. Follow-up data was collected for all cases (follow-up period: 2 m-10 years). The χ2 test was used to determine the significance of outcome in marker expression.
Results: Total 32 patients with HGEEA diagnosis were retrieved with mean age 70 (37-88). 22 had classic morphology of HGEEA; cells in solid areas were similar to the cells forming glands. Immunophenotypes and outcomes for 22 HGEEA cases were: 5 p53 overexpression (22.7%), all dead of disease (DOD); 17 p53- (77.3%), 4 DOD; 7 ER/PR-/- (31.8%), 6 DOD; 15 ER/PR+/+ (68.2%), 3 DOD; all 22 cases were diffusely positive for CK, EMA, vimentin; increased mitotic activities (MIB1+) were observed in 21 cases (95.5%); p16+ in 17 cases (77.3%). 10 cases with HGEEA diagnosis were misclassified: 5 exhibited features of undifferentiated CA, characterized by pattern less solid growth of tumor cells with marked nuclear atypia, occasional rhabdoid forms, frequent mitoses, necrosis. CK and EMA were only focally +. Other 5 misclassified tumors were: 2 clear cell CA, 2 adenosquamous CA, and 1 serous CA. Immunophenotypes and outcomes for 10 misclassified tumors were: 8 DOD, 7 p53 overexpression, 7 ER/PR-/-, 10 p16+, and 9 vimentin+. 5 undifferentiated CA exhibited p53 over expression (4/5) and completely loss ER/PR expression (5/5).
Conclusions: 1) HGEEA immunophenotypical overlaps with type II tumors. HGEEA with p53 overexpression (22.7%) and loss of ER/PR expression (31.8%) were associated with adverse outcome (p<0.01). 2) Non-endometrioid CA (type II tumors), more frequently undifferentiated CA, could be misinterpreted as HGEEA and more often had p53 overexpression (70%) and loss of ER/PR expression (80%), and were associated with adverse outcome (p<0.01). 3) Increased proliferative activity (MIB-1+), p16 and vimentin expression were commonly seen in both HGEEA and type II tumors, not associated with adverse outcome.
Category: Gynecologic & Obstetrics

Monday, February 28, 2011 9:30 AM

Poster Session I Stowell-Orbison/Surgical Pathology/Autopsy Awards Poster Session # 134, Monday Morning

 

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