title: Diagnostic role of inhibin α-subunit and inhibin/activin β-subunit in adrenal cortical and medullary tumors in Egyptian patients.
abstract: Inhibin and activins are dimeric glycoproteins that are structurally and functionally related to transforming growth factor-β and are composed of 1 α-subunit and 1 of 2 β-subunits (βA or βB). In recent years, there has been controversy about their role in adrenal tumors and their suitability as a diagnostic/predictive marker. Inhibin α and inhibin/activin β protein expression was assessed on 47 adrenal tissue specimens by means of immunohistochemistry. Positive immunoreactivity of inhibin-α was seen in all studied hyperplastic adrenal glands, 90.9% of cortical adenomas, and 83.3% of adrenal cortical carcinomas. In contrast, the adrenomedullary neoplasms had a statistically significantly different behavior (P=0.001). We observed the negative expression of inhibin α in 85% and 80% of benign and malignant pheochromocytomas, respectively. As regards the immunoreactivity of inhibin/activin β, 80% of adrenal hyperplasias, 81.8% of cortical adenomas, and 83.3% of adrenal cortical carcinomas showed positivity. Strong-to-weak positive staining of inhibin/activin β was observed in 70% of benign pheochromocytomas, whereas malignant pheochromocytomas showed positive immunohistochemical staining in 40% of cases with weak intensity. The scoring of inhibin/activin β immunoreactivity between adrenocortical and adrenomeullary neoplasia failed to reach the significant value (P=0.1). Our results demonstrate that inhibin α had a diagnostic role, differentiating between the adrenocortical and adrenomedullary neoplasms. Moreover, inhibin/activin β might play a predictive role for malignant potential in pheochromocytoma. Further studies are warranted to determine whether they play a diagnostic/predictive role in adrenal tumors or are just surrogate markers for this group of neoplasia.
authors.affiliation: Department of Pathology, Minia University, Minia, Egypt. annglasgow@hotmail.com
authors.forename: Hanan Mohammed Abd
authors.initials: HM
authors.lastname: Elmoneim
authors.forename: Rehab Monir
authors.initials: RM
authors.lastname: Samaka
authors.forename: Hanan
authors.initials: H
authors.lastname: Ali
mesh_terms: D000310:Adrenal Gland Neoplasms / Q000175:diagnosis* / Q000378:metabolism; D018246:Adrenocortical Adenoma / Q000175:diagnosis* / Q000378:metabolism; D018268:Adrenocortical Carcinoma / Q000175:diagnosis* / Q000378:metabolism; D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000378:metabolism*; D020295:Brain Stem Neoplasms / Q000175:diagnosis* / Q000378:metabolism; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D028322:Inhibin-beta Subunits / Q000378:metabolism*; D007265:Inhibins / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D010673:Pheochromocytoma / Q000175:diagnosis* / Q000378:metabolism; D011379:Prognosis; D012680:Sensitivity and Specificity
chemical_list: D014408:Biomarkers, Tumor; C103008:inhibin beta A subunit; C094377:inhibin-alpha subunit; D007265:Inhibins; D028322:Inhibin-beta Subunits