Chromosomal alterations in low-grade endometrial stromal sarcoma and undifferentiated endometrial sarcoma as detected by comparative genomic hybridization

Endometrial stromal sarcomas (ESS) are very rare neoplasms constituting less than 0.5% of all malignant uterine tumors. The aim of the present study was to characterize the karyotypic abnormalities in these malignant mesenchymal tumors and to find specific chromosomal aberrations with eventual correlation with histologic grades. Twelve cases of endometrial stromal sarcomas consisting of nine low-grade ESS and three undifferentiated endometrial sarcomas (UES) were investigated by comparative genomic hybridization (CGH). Ten of the twelve cases (83.3%) displayed chromosomal gains or losses. Deletions occurred more frequently than gains (63.4% versus 36.6%). In low-grade ESS, gains on 1, 6q, 9q, 16p, 19, 20q, 22q and losses on 2, 4q, 6, 7, 11q, 13q, 15q, 16q, 20p, X were detected. CGH with UES exhibited gains on 2q, 4q, 6q, 7p, 9q, 20q and losses on 3q, 10p, 14q. One low-grade ESS and one UES did not reveal any chromosomal aberration. Chromosomal aberrations in endometrial sarcomas are heterogeneous and do not clearly correlate with the histologic grades. There is no increased accumulation of aberrations from low-grade ESS to UES. Despite the karyotypic variations, chromosomal deletion on 7p was the most common finding (55.6%) in low-grade ESS and may play a role in tumor development and progression.