[1048] The Pathogenesis of Uterine and Extrauterine Carcinosarcoma Appear Similar 
An Immunohistochemical Study of PTEN Expression
BA Ologun, MR Quddus, CJ Sung, WD Lawrence. Women & Infants Hospital & The Warren Alpert Medical School of Brown University, Providence, RI
Background: Carcinosarcomas are an intriguing group of mullerian-derived malignant tumors consisting of mixtures of both epithelial and mesenchymal components. These tumors arise primarily in the uterine corpus, however, also seen in extrauterine locations e.g., ovary, fallopian tube, and omentum. The current study compares the pattern of PTEN expression of uterine carcinosarcomas and extra-uterine carcinosarcomas.
Design: Thirty-seven high-grade mullerian carcinosarcoma cases were obtained from the archival files of Women & Infants. These included 24 uterine cases, and 13 extra-uterine (9 ovarian cases, 2 cervical cases, 2 pelvic cases, and 1 mesenteric) cases. Four 
m sections were cut from each block and all slides were stained with antibodies to PTEN (Cascade Bioscience, Winchester, MA). The presence of the area(s) chosen for study was confirmed with H&E staining and positive and negative control slides were run with each batch of staining. Kruskal-Wallis test used for statistical analysis.
Results:
| PTEN Null in both Carcinoma & Sarcoma Component | PTEN Expression Retained In both Carcinoma & Sarcoma Component | PTEN Expression Equivocal | PTEN Expression Discordent | |
| uterine Carcinosarcoma (n=23) | 20 (87%) | 1 (4%) | 1 (4%) | 1 (4%) |
| Extra-Uterine Carcinosarcoma (n=14) | 11 (78%) | 1 (7%) | 2 (14%) | 0 |
| PTEN Null In both Carcinoma & Sarcoma Component | PTEN Expressed in both Carcinoma & Sarcoma Component | PTEN EXpression Equivocal | PTEN Expression Discordent | |
| Uterine Carcinosarcoma (n=23) | 20 (87%) | 1 (4%) | 1 (4%) | 1 (4%) |
| Ovariasn Carcinosarcoma (n=9) | 7 (78%) | 0 | 2 (22%) | 0 |
Conclusions: 87% uterine and 78% extrauterine carcinosarcomas were PTEN NULL in both carcinomatous and sarcomatous components. Likewise, the majority of ovarian carcinosarcomas (78%) also exhibited a concordant PTEN NULL phenotype. Kruskal-Wallis test (a non-parametric ANOVA), showed that there was no significant difference in PTEN expression pattern between uterine and extra-uterine carcinosarcomas (p value = 0.1102) or uterine carcinosarcomas vs. ovarian carcinosarcomas (p= 0.0657). The high frequency of PTEN NULL concordance in uterine, extra-uterine and ovarian carcinosarcomas, suggests that the pathogenesis of uterine and extra-uterine carcinosarcomas is similar.
Category: Gynecologic
Wednesday, March 11, 2009 1:00 PM
Poster Session VI # 163, Wednesday Afternoon