[983] Differential Expression of IMP3 between Male and Female Mature Teratomas.

Liping Zhang, Liang Cheng, Zhong Jiang. Umass Memorial Medical Center, Worcester, MA; Indiana University School of Medicine, Indianapolis

Background: Ovarian mature teratoma is benign, whereas mature teratoma components in adult testicular germ cells tumors are considered malignant since they have a metastatic potential and often resistant to chemotherapy. Although different theories have been postulated, no biological marker is found so far related to such gender and clinical difference. IMP3, an oncofetal protein plays an important role in embryogenesis and carcinogenesis of certain malignant neoplasms. Several studies have shown that IMP3 is a cancer specific biomarker. In this study, we analyzed IMP3 expression in germ cell tumors, especially compared its expression between male and female teratomas.
Design: Total of 195 germ cell tumors (77 male patients with testicular germ cell tumors without teratoma components including 22 seminomas; 55 non seminomatous germ cell tumors ; 37 male patients with testicular non seminomatous germ cell tumors with teratoma components; 54 female patients with ovarian mature teratomas; 27 male patients with metastatic germ cell tumors with teratoma components) obtained from archives of two large Academic Medical Center were examined by immunohistochemistry for IMP3 expression.
Results: IMP3 are stained in germ cell tumors by immunohistochemical method, as illustrated in Figure 1. IMP3 expression is present in 99% (76/77) male testicular germ cell tumors without teratoma components. The expression is present in 100% (37/37) tumors with teratoma components. Similarly, IMP3 expression is present in 100% (27/27) male metastatic teratomas. In contrast, IMP3 expression is present in only 7% (4/54) of female mature teratomas. IMP3 expression however is also seen in normal spermatogonia and intratubular germ cell neoplasia.

Conclusions: Differential expression of IMP3 between male and female mature teratomas demonstrates that IMP3 may play an important role for the metastasis of testicular germ cell tumors. As IMP3 is highly expressed in male germ cell tumors including all mature teratoma components, IMP3 may serve as a potential tissue biomarker to distinguish metastatic teratoma from its benign mimickers, especially in the setting of status post chemotherapy for germ cell tumors.
Category: Genitourinary (including renal tumors)

Tuesday, March 1, 2011 1:00 PM

Poster Session IV # 75, Tuesday Afternoon


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