Expression of OCT4 in the primary germ cell tumors and thymoma in the mediastinum.
Primary germ cell tumors (GCTs) and thymoma are both located in the anterior mediastinum. A previous study has postulated that octamer binding transcription factor (OCT4) is a nuclear transcription factor that is expressed in pluripotent embryonic germ cells. This study examined OCT4 expression in GCTs and thymoma originating from the mediastinum. A retrospective study included 46 consecutive patients with GCTs conducted between 1983 and 2005, and 22 consecutive thymoma in the mediastinum whose tumors had been surgically excised. The 46 primary GCTs in mediastinum included teratoma (n=27; 58.7%), seminoma (n=10; 21.7%), yolk sac tumor (n=6; 13%), embryonal carcinoma (n=1; 2.1%), and mixed GCTs (n=2; 4%; one consisted of teratoma and yolk sac tumor, and the other teratoma, yolk sac tumor, and seminoma); and 22 thymoma including World Health Organization type A (n=3, 13.6%), type AB (n=4, 18.2%), type B1 (n=6, 27.3%), type B2 (n=4, 13.6%), and type B3 (n=5, 22.7%). Each tumor was examined with hematoxylin and eosin staining, and with antibodies to OCT4. All 10 seminoma cases, 1 embryonal carcinoma case, and 1 mixed GCT case containing seminoma were immunopositive for OCT4. On the other hand, the 22 thymoma, 6 yolk sac tumor, 27 teratomas, and 1 case with mixed GCT without component of seminoma were immunonegative for OCT4. We conclude that immunostaining with antibodies to OCT4 is a useful diagnostic tool in the identification of seminomas and primary embryonal carcinomas in GCTs originating from the mediastinum.
Jung
Shih-Ming
SM
Department of Pathology, Chang Gung Children Hospital, Taipei, Taiwan.
Chu
Pao-Hsien
PH
Shiu
Tzu-Fang
TF
Wu
Hsueh-Hua
HH
Kuo
Tseng-Tong
TT
Chu
Jaw-Ji
JJ
Lin
Pyng-Jing
PJ
D000911:Antibodies, Monoclonal / Q000378:metabolism*; D014408:Biomarkers, Tumor / Q000032:analysis*; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008479:Mediastinal Neoplasms / Q000378:metabolism*; D008482:Mediastinum / Q000473:pathology*; D009373:Neoplasms, Germ Cell and Embryonal / Q000378:metabolism*; D018239:Seminoma / Q000378:metabolism*; D013736:Testicular Neoplasms / Q000378:metabolism*; D013945:Thymoma / Q000378:metabolism*; D013953:Thymus Neoplasms / Q000378:metabolism*
D000911:Antibodies, Monoclonal; D014408:Biomarkers, Tumor; C079851:OKT4A monoclonal antibody