[991] Recurrent Chromosomal Aberrations in Specialized Stromal Tumors of the Prostate Detected by Array Comparative Genomic Hybridization

Chin-Chen Pan, Jonathan I Epstein. Taipei Veterans General Hospital, Taipei, Taiwan; Johns Hopkins Medical Institutions, Baltimore, MD

Background: Specialized stromal tumors of the prostate encompass stromal sarcoma and stromal tumors of uncertain malignant potential (STUMP). These are neoplasms with unique local morbidity and malignant potential. However, the molecular signature associated with stromal sarcoma and STUMP has not been unraveled. The study was conducted to detect the chromosomal imbalances in stromal sarcoma and STUMP by using Array Comparative Genomic Hybridization (aCGH).
Design: The study consisted of 2 cases of stromal nodule, 7 cases of STUMP (4 degenerative type, 1 hypercellular type, 2 myxoid type) and 4 cases of stromal sarcoma including a distant metastasis developed metachronously after a primary stromal sarcoma of the prostate. DNA was extracted from the representative paraffin-embedded formalin-fixed specimens and was submitted for aCGH.
Results: All stromal sarcomas and 6 of 7 STUMP revealed chromosomal aberrations. One myxoid type of STUMP and the 2 stromal nodules showed normal chromosome copy numbers. Overall, the most common alteration was loss of chromosome 13 (9 cases), followed by loss of chromosome 14 (8 cases) and loss of chromosome 10q (6 cases). Sporadic losses were found in chromosomes 16, 20p (each 3 cases) and 4q, 5, 6, 9, 11 (each 2 cases), and gains on chromosomes 19 and 21 (each 2 cases). Except one stromal sarcoma which showed a distinct chromosomal profile, other stromal sarcomas showed a similar pattern to those of STUMP.
Conclusions: Stromal sarcoma and STUMP shared similar profiles of chromosomal imbalances (mainly losses of chromosomes 10p, 13 and 14). From a molecular genetic perspective, the recurrent chromosomal alterations support the concept of specialized stromal tumors of the prostate as a distinctive tumor entity.
Category: Genitourinary (including renal tumors)

Monday, March 4, 2013 1:00 PM

Poster Session II # 143, Monday Afternoon


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