The accurate classification and proper identification of testicular germ cell tumors is imperative for treatment selection and clinical prognosis. Although such distinction can often be achieved by microscopic morphology alone, ancillary tests may at times be needed. T-cell factor 7 L1 (TCF7L1, also known as TCF3), a component of the Wnt signaling pathway, plays important roles in embryonic stem cell self-renewal and lineage specification. Here we examined the immunohistochemical expression and diagnostic utility of TCF7L1 in testicular germ cell tumors. Fifty cases of testicular germ cell tumors were collected, including 23 seminomas, 6 embryonal carcinomas, 1 teratoma, 1 choriocarcinoma, and 19 mixed germ cell tumors. The components of the mixed germ cell tumors were seminoma (n = 3), embryonal carcinoma (n = 18), yolk sac tumor (n = 9), teratoma (n = 15), and choriocarcinoma (n = 4). On immunohistochemistry of TCF7L1, only nuclear staining was considered positive. Staining was graded as negative (<5% of tumor cells stained), minimal (5-25% positive), focal (26-50%), and diffuse (>50%). All non-seminomatous components (n = 54) exhibited distinct nuclear expression of TCF7L1 (54/54; 100%). In contrast, no TCF7L1 expression was detected in the majority of seminomatous tumor component (24/26; 92%). Two seminomas (2/26; 8%) exhibited minimal weak nuclear staining (5% and 10%, respectively) for TCF7L1. In conclusion, TCF7L1, highly expressed in non-seminomatous testicular germ cell tumors, might be used as a marker for diagnosis of testicular germ cell tumors, two therapeutically different entities, for better patient management.
Experimental and molecular pathology. 2019 Aug 02 [Epub]
Lihong Bu, Qi Yang, Loralee McMahon, Guang-Qian Xiao, Faqian Li
Department of Laboratory Medicine and Pathology, University of Minnesota, 420 Delaware Street SE, Minneapolis, MN 55455, United States of America., Department of Pathology and Laboratory Medicine, University of Rochester Medical Center, 601 Elmwood Avenue, Rochester, NY 14642, United States of America., Department of Pathology and Laboratory Medicine, University of Rochester Medical Center, 601 Elmwood Avenue, Rochester, NY 14642, United States of America; Department of Pathology, Keck School of Medicine, University of Southern California, 2011 Zonal Avenue, Los Angeles, CA 90089, United States of America., Department of Laboratory Medicine and Pathology, University of Minnesota, 420 Delaware Street SE, Minneapolis, MN 55455, United States of America; Department of Pathology and Laboratory Medicine, University of Rochester Medical Center, 601 Elmwood Avenue, Rochester, NY 14642, United States of America; Lillehei Heart Institute and Masonic Cancer Center, University of Minnesota, Minneapolis, MN 55455, United States of America. Electronic address: .