[778] Molecular Genetic Evidence Supporting the Neoplastic Nature of Fibrous Stroma in Testicular Teratoma.

Liang Cheng, Shaobo Zhang, Stephen DW Beck, Richard S Foster, Thomas M Ulbright. Indiana University, Indianapolis

Background: Testicular teratoma consists of heterogeneous mixtures of diverse epithelial and stromal components. The biological nature and genetic characteristics of the fibrous stroma have not been adequately investigated.
Design: The fibrous stroma and other components from 21 testicular teratoma patients were investigated separately for chromosome 12 anomalies, including isochromosome 12p [i(12p)] and 12p overrepresentation using interphase fluorescence in situ hybridization analysis. All the cases contained only teratoma in the orchiectomy specimens.
Results: Overall, 90% (19/21) of the cases of fibrous stroma had chromosome 12p abnormalities. Isochromosome 12p was detected in 11 of 21 (52%) cases of fibrous stroma, and chromosome 12p overrepresentation was detected in 13 of 21 (62%) cases of fibrous stroma. Among the 11 cases of i(12p)-positive fibrous stroma, 5 (45%) also had 12p overrepresentation. Five of the 13 (38%) cases of fibrous stroma with 12p overrepresentation also had i(12p). Only 2 of 17 cases (12%) of fibrous stroma showed neither 12p overrepresentation nor the presence of i(12p). Isochromosome (12p) and 12p overrepresentation were identified in the gastrointestinal epithelium of 12/17 (71%) and 15/17 (88%) cases; in the respiratory epithelium of 3/8 (38%) and 6/8 (75%) cases; in the squamous epithelium of 5/7 (71%) and 5/7 (71%) cases; and in the cartilage of 4/5 (80%) and 0/5 (0%) cases, respectively. Concordant chromosomal 12p abnormalities were observed between the fibrous stroma and epithelial elements of testicular teratomas.
Conclusions: Our results show that the fibrous stroma of testicular teratomas frequently has genetic abnormalities similar to those of the teratomatous epithelial components. Concordant chromosome 12p alterations between the fibrous stroma and teratomatous epithelial elements provide further evidence that both epithelial and fibrous components of teratoma are derived from a common progenitor.
Category: Genitourinary (including renal tumors)

Tuesday, March 1, 2011 1:00 PM

Poster Session IV # 82, Tuesday Afternoon

 

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