Diagnostic Utility of JAZF1/JJAZ1 Fusion Gene in Endometrial Stromal Sarcoma of the Uterus.
Sang-Ryung Lee, Jene Choi, Hyung Kyung Kim, Yonghee Lee, Kyu-Rae Kim. University of Ulsan College of Medicine, Seoul, Korea
Background: Diagnosis of endometrial stromal sarcoma (ESS) is usually not problematic in most cases because of their characteristic histopathologic findings. However, when the tumors have extensive secondary differentiation, including smooth muscle, myxoid, fibrous, ovarian sex cord-like/epithelioid, or endometrioid glandular differentiation, correct diagnosis can be very difficult. Recently, the presence of the JAZF1/JJAZ1 gene fusion in endometrial stromal sarcoma has been described, but the incidence has been variably described, and the applicability of the fusion gene in the difficult cases has not been cofirmed. In this study, we analyzed the prevalence of JAZF1/JJAZ1 gene fusion in classical low-grade endometrial stromal sarcomas (n=15) and those with various secondary differentiation (n=13) to examine the applicability of JAZF1/JJAZ1 gene fusion in the diagnosis of difficult cases of ESS showing secondary differentiation.
Design: JAZF1/JJAZ1 fusion transcript were analyzed using nested RT-PCR in 28 cases including classical low-grade ESSs (n=15), those with smooth muscle differentiation (n=3), endometrial glandular differentiation (n=2), and with osseous metaplasia (n=1), undifferentiated endometrial sarcoma (UES) (n=5), UES with sex cord-like differentiation (n=1), combined low-grade ESS and UES (n=1).
Results: The fusion transcript was detected in 18 (85.7%) of 21 low-grade ESSs and in 2 (28.6%) of 7 UESs, and the positive cases of low-grade ESSs included 14 classical ESS, one with smooth muscle differentiation (33%), two with endometrial glandular differentiation (100%), and one with osseous metaplasia (100%), and two UESs combined with classical low grade ESS. Direct sequencing analysis of DNA in 2 cases confirmed a fusion of JAZF1 and JJAZ1 genes forming a new amino acid (glutamic acid), which was previously described in the literature.
Conclusions: JAZF1/JJAZ1 fusion gene was identified in a significant proportion of low-grade ESS regardless of the presence or absence of secondary differentiation, thus, this method can be useful in the diagnosis of difficult cases of ESS.
Category: Gynecologic & Obstetrics
Wednesday, March 2, 2011 1:00 PM
Poster Session VI # 189, Wednesday Afternoon