title: Immunohistochemical expression of monoclonal antibody 43-9F in testicular germ cell tumours.
abstract: The aim of this study was to evaluate the clinical utility of immunohistochemical staining of human testicular germ cell tumours with the monoclonal antibody 43-9F to distinguish embryonal carcinoma (EC) from other malignant germ cell components in order to facilitate pathohistological assessment of prognostic risk factors for metastatic disease in clinical stage I NSGCT. Archival, formalin-fixed, paraffin-embedded tissue blocks of 24 classical seminomas, 7 spermatocytic seminomas, and 20 non-seminomatous germ cell tumours were stained for 43-9F, AFP, hCG and PLAP expression. Immunohistochemical expression was graded using a semi-quantitative scoring system: 1+ = 0-25%, 2+ = 26-50%, 3+ = 51-75% and 4+ = 76-100%. Positive immunohistochemical staining for 43-9F was found in all embryonal carcinomas and yolk sac tumours (YST); staining intensity was not statistically different between the two tumours (3.8 +/- 1.2 vs. 3.1 +/- 0.9). Classical seminomas and seminomatous components of NSGCT stained positive in 13/24 cases (54%); staining intensity was weak to moderate (1.1 +/- 0.7) in all but two cases (4+). Spermatocytic seminomas demonstrated weak positive immunostaining in 2/7 cases (29%). Adjacent CIS was found in 33/54 (61.1%) of tumours and 24/33 (72.7%) of CIS cells exhibited a weak to moderate staining intensity (1.4 +/- 0.7). AFP expression was found in 93% of YST and in only 10% of EC; however, based on the focal staining pattern, adequate differentiation of YST and EC was not possible. Positive PLAP staining was observed in 75% of EC, 79% of seminomas and in 88% of CIS cells. We did not find 43-9F staining clinically useful to distinguish embryonal carcinoma from other germ cell tumour components such as yolk sac tumour. The detection rate of CIS by 43-9F immunohistochemical staining was low and combination of PLAP staining with light microscopy was even superior. Additionally, our study confirms the link between pre-invasive CIS and embryonal carcinoma and suggests the possible direct development of embryonal carcinoma from CIS.
authors.affiliation: Department of Surgery, Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA.
authors.forename: A
authors.initials: A
authors.lastname: Heidenreich
authors.forename: I A
authors.initials: IA
authors.lastname: Sesterhenn
authors.forename: F K
authors.initials: FK
authors.lastname: Mostofi
authors.forename: J W
authors.initials: JW
authors.lastname: Moul
mesh_terms: D000469:Alkaline Phosphatase / Q000032:analysis; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D015295:Antigens, Tumor-Associated, Carbohydrate / Q000096:biosynthesis* / Q000276:immunology; D014408:Biomarkers, Tumor; D006063:Chorionic Gonadotropin / Q000032:analysis; D018237:Germinoma / Q000201:enzymology / Q000276:immunology* / Q000473:pathology; D006801:Humans; D007124:Immunoenzyme Techniques; D007527:Isoenzymes / Q000032:analysis; D008297:Male; D051379:Mice; D009373:Neoplasms, Germ Cell and Embryonal / Q000201:enzymology / Q000276:immunology* / Q000473:pathology; D018239:Seminoma / Q000201:enzymology / Q000276:immunology* / Q000473:pathology; D013094:Spermatozoa / Q000276:immunology*; D013194:Staining and Labeling; D013737:Testis / Q000201:enzymology*; D000509:alpha-Fetoproteins / Q000032:analysis
chemical_list: D000911:Antibodies, Monoclonal; D015295:Antigens, Tumor-Associated, Carbohydrate; D014408:Biomarkers, Tumor; D006063:Chorionic Gonadotropin; D007527:Isoenzymes; D000509:alpha-Fetoproteins; C055791:germ-cell AP isoenzyme; C076831:tumor-associated antigen 43-9F; D000469:Alkaline Phosphatase