[1045] Thyroid Transcription Factor-1 Expression in Benign Gynecologic Tissues

H Niu, VA LiVolsi, TL Pasha, PJ Zhang. Guangzhou Children's Hospital, Guangzhou, China; Hospital of University of Pennsylvania, Philadelphia

Background: Thyroid transcription factor-1 (TTF-1) is a 38-kd nuclear protein, a member of the NKx2 family of homeodomain transcription factors. It is highly expressed in normal and neoplastic thyroid and lung tissues and considered as a reliable marker for lung adenocarcinoma and thyroid carcinoma. Recently, expression of TTF-1 has also been reported in ovarian, endometrial and endocervical epithelial neoplasms. Little was known for TTF-1 immunoreactivity in normal gynecologic tissues. In this study, TTF-1 expression in various non-neoplastic gynecologic tissues was investigated.
Design: 108 normal gynecologic tissues including 28 endometria (12 proliferative, 11 secretory, 5 inactive), 26 fallopian tubes, 28 cervixes (14 endocervical, 14 ectocervical), 14 myometria and 12 ovaries were studied. Tissues were routinely-processed surgical specimens from adult patients with non-neoplastic conditions. In addition, 4 normal fallopian tubes and 2 ovaries from 4 pediatric patients (aged from 3 months to 11 years) were evaluated. Monoclonal antibody (SPT24) was applied on Refine/Bond Max autostainer. Nuclear TTF-1 immunoreactivity was evaluated and recorded.
Results: Variable TTF-1 nuclear reactivity was identified in 25 of 26 (96%) fallopian tubes (positive percentage ranged 2-60%, median 25%), 15 of 28 (54%) endometria (1-10%, median 5%), and 6 of 14 (43%) endocervical samples (<5%). TTF-1 was also identified in 2 of 4 (50%) pediatric fallopian tubes with 5% and 20% of the tubal epithelium being positive, respectively. No TTF-1 expression was detected in ovarian tissue (neither epithelium nor stroma; neither adult nor pediatric samples), ectocervical squamous epithelium, myometrium, and all stromal tissue in endometrium, tube and cervix. TTF-1 reactivity was detected in both proliferative and secretory endometria but not in inactive endometria.
Conclusions: 1) In addition to gynecologic epithelial tumors, TTF-1 is frequently expressed in normal/non-neoplastic tubal (96%), endometrial (54%) and endocervical (43%) epithelia. 2) TTF-1 might have a role in the function and development of normal fallopian tube and endometrium as it is highly expressed in tubal epithelium of both adults and children, and in functional endometrium but not in inactive endometrium. 3) The high TTF-1 expression in tubal epithelium but not in normal ovarian surface epithelium suggests that some of the TTF-1 positive ovarian tumors might be related to the TTF-1 positive tubal epithelium.
Category: Gynecologic

Tuesday, March 10, 2009 1:00 PM

Poster Session IV # 168, Tuesday Afternoon