title: Inhibin immunohistochemistry applied to ovarian neoplasms: a novel, effective, diagnostic tool.
abstract: Immunohistochemistry using monoclonal antibodies against human inhibin, a peptide hormone produced by ovarian granulosa cells to inhibit follicle-stimulating hormone (FSH), has been recently applied to diagnostic anatomic pathology. This investigation hypothesizes that inhibin immunohistochemistry will aid in the crucial clinical distinction between sex cord-stromal and other primary ovarian neoplasms. Available H&E slides and clinical information from a retrospective surgical series of 186 primary ovarian tumors were reviewed to verify diagnoses, and representative paraffin sections were immunostained with anti-inhibin (R1 monoclonal, Serotec, Kidlington, Oxford, UK). Immunoreactivity was graded as weak/strong (W/S), and the proportion of strong staining cells was coded as follows: S1 = <10%, S2 = 10%-50%, S3 = >50%, respectively. Inhibin immunoreactivity for 137 sex cord-stromal lesions was as follows: 100% of 66 granulosa cell tumors: 80% S3, 20% S2; 100% of 17 Sertoli-stromal tumors: 90% S3, 10% S2; 100% of 13 hyperplastic follicular/stromal lesions: 90% S3, 10% S2; 100% of six steroid cell tumors: 100% S3; 90% of 18 thecomas: 40% S3, 10% S2, 10% S1, 30% W; 0% of 12 fibromas, three myxomas, and two sclerosing stromal tumors. None (0 of 49) of the other ovarian neoplasms exhibited inhibin: 22 carcinomas, 12 carcinosarcomas, seven small cell carcinomas, six germ cell tumors, and two lymphomas. In the typical case, the distinction between sex cord-stromal and other ovarian neoplasms requires nothing more than routine pathological examination. In diagnostically challenging cases, our data indicate that inhibin immunohistochemistry is a very useful adjunct because granulosa and sertoli-stromal tumors are positive whereas other potential mimickers have been negative thus far.
authors.affiliation: University of California-Davis Medical Center, Sacramento 95817, USA.
authors.forename: M J
authors.initials: MJ
authors.lastname: Costa
authors.forename: P F
authors.initials: PF
authors.lastname: Ames
authors.forename: J
authors.initials: J
authors.lastname: Walls
authors.forename: L M
authors.initials: LM
authors.lastname: Roth
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000911:Antibodies, Monoclonal; D002648:Child; D002675:Child, Preschool; D005260:Female; D006106:Granulosa Cell Tumor / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D007223:Infant; D007265:Inhibins / Q000276:immunology / Q000378:metabolism*; D008875:Middle Aged; D018396:Mucin-1 / Q000378:metabolism; D018309:Neoplasms, Gonadal Tissue / Q000378:metabolism; D010051:Ovarian Neoplasms / Q000175:diagnosis* / Q000378:metabolism* / Q000473:pathology; D012707:Sertoli Cell Tumor / Q000378:metabolism; D018310:Sertoli-Leydig Cell Tumor / Q000378:metabolism; D018312:Sex Cord-Gonadal Stromal Tumors / Q000378:metabolism / Q000473:pathology
chemical_list: D000911:Antibodies, Monoclonal; D018396:Mucin-1; D007265:Inhibins