OBJECTIVETo study the immunohistochemical expression of OCT4, CD117 and CD30 in germ cell tumors and to assess their diagnostic value.

METHODSImmunohistochemical study for OCT4 was performed on formalin-fixed, paraffin-embedded tissues of 63 cases of germ cell tumors, including seminoma (21), dysgerminoma (7), germinoma (8), embryonal carcinoma (8), yolk sac tumor (6), mature teratoma (10) and immature teratoma (3), as well as 25 cases of non-germ cell tumors, including granulosa cell tumor (8), clear cell adenocarcinoma (4), Leydig's cell tumor (5), diffuse large B-cell lymphoma (4) and malignant melanoma (4). Besides, the expression of CD117 and CD30 in all germ cell tumors was studied.

RESULTSAll cases of seminoma and germinoma, 6/7 cases of dysgerminoma and 7/8 cases of embryonal carcinoma were positive for OCT4, with strong nuclear staining. All other germ cell tumors and non-germ cell tumors were negative for OCT4, except for 1 case of yolk sac tumor and 1 case of clear cell adenocarcinoma which showed weak staining. Positive membranous expression of CD117 was demonstrated in 19/21(90.5%) seminoma, 5/7 dysgerminoma and 7/8 germinoma. Focal weak membranous staining was also noted in 1 case of yolk sac tumor. The melanocytes in teratoma were also positive for CD117. All cases of embryonal carcinoma were negative. On the other hand, positive membranous expression of CD30 were demonstrated in 6/8 embryonal carcinoma. One case of germinoma and 1 case of yolk sac tumor showed weak cytoplasmic positivity. All cases of seminoma and dysgerminoma, 7/8 germinoma and all cases of teratoma were negative for CD30.

CONCLUSIONSOCT4 is a sensitive and relatively specific marker for diagnosing seminoma, dysgerminoma, germinoma and embryonal carcinoma. CD117 and CD30 immunostains, when used in combination, represent valuable tools for distinguishing embryonal carcinoma and seminoma, dysgerminoma, germinoma.

Carcinoma, Embryonal ; metabolism ; pathology ; Diagnosis, Differential ; Dysgerminoma ; metabolism ; pathology ; Endodermal Sinus Tumor ; metabolism ; pathology ; Female ; Germinoma ; metabolism ; pathology ; Humans ; Ki-1 Antigen ; metabolism ; Male ; Neoplasms, Germ Cell and Embryonal ; metabolism ; pathology ; Octamer Transcription Factor-3 ; metabolism ; Ovarian Neoplasms ; metabolism ; pathology ; Proto-Oncogene Proteins c-kit ; metabolism ; Seminoma ; metabolism ; pathology ; Teratoma ; metabolism ; pathology ; Testicular Neoplasms ; metabolism ; pathology

Twenty-one cases of seminoma (including testicular seminoma, ovarian dysgerminoma and extragonadal germinoma) were reviewed for the cell types responsible for the production of alpha-fetoprotein (AFP) and human chorionic gonadotropin (HCG). Histologically the cases included seventeen classical seminomas and 4 anaplastic seminomas. The latter had some mononuclear and multinuclear giant cells. All 4 patients with anaplastic seminoma had elevated levels of serum AFP, and each of these cases contained AFP producing tumor cells identified by immunoperoxidase staining. All seminomas of patients with elevated serum levels of HCG were of the classical type but HCG producing tumor cells could not be identified by immunoperoxidase staining. Immunoreactivity to anti-AFP was found in some large mononuclear cells and anaplastic cells. To explain these results, we propose that the large mononuclear cell is a multipotential cell capable of differentiating into a germ cell, yolk sac and embryo, and that the anaplastic seminoma cells might represent a stage on the continuum of cellular differentiation from the large mononuclear cells to germ cells. The multinuclear giant cell does not appear to be essential for the production of either AFP or HCG in seminoma.
Adolescent ; Adult ; Child ; Chorionic Gonadotropin/metabolism ; Dysgerminoma/metabolism/*pathology ; Female ; Human ; Immunohistochemistry ; Male ; Middle Age ; Ovarian Neoplasms/metabolism/pathology ; Support, Non-U.S. Gov't ; Testicular Neoplasms/metabolism/pathology ; alpha-Fetoproteins/biosynthesis

Adolescent ; Alkaline Phosphatase ; metabolism ; Antineoplastic Combined Chemotherapy Protocols ; therapeutic use ; Bleomycin ; therapeutic use ; Cisplatin ; therapeutic use ; Diagnosis, Differential ; Dysgerminoma ; pathology ; Etoposide ; therapeutic use ; Female ; Gonadoblastoma ; drug therapy ; metabolism ; pathology ; surgery ; Humans ; Hysterectomy ; methods ; Inhibins ; metabolism ; Isoenzymes ; metabolism ; Ovarian Neoplasms ; drug therapy ; metabolism ; pathology ; surgery ; Young Adult