title: Expression of calretinin and the alpha-subunit of inhibin in granular cell tumors.
abstract: Granular cell tumors (GCTs) typically express S-100 protein, which has been used as a marker in differential diagnosis. Calretinin, a calcium-binding protein related structurally to S-100, and inhibin, a polypeptide hormone secreted primarily by ovarian granulosa cells and testicular Sertoli cells and functioning as an inhibitor for pituitary follicle-stimulating hormone secretion, are potentially useful but not well-evaluated markers for GCTs. We studied 43 cases of GCT with antibodies to calretinin, the inhibin alpha-subunit, and S-100 protein. All tumors were positive for inhibin alpha-subunit and S-100 protein, with 50% or more cells showing moderate to strong staining. Forty tumors (93%) were positive for calretinin, ranging from focal weak to diffuse strong staining. Enhanced staining for calretinin in the tumor cells adjacent to hyperplastic squamous epithelium was observed in 9 of 13 cases showing pseudoepitheliomatous hyperplasia. Calretinin and the inhibin alpha-subunit are useful markers for GCTs. The expression of calretinin, a primarily neuronal protein, in GCTs further supports its neural differentiation or derivation. The elevated calretinin expression in the tumor cells adjacent to the hyperplastic squamous epithelium suggests a role for calretinin in the tumor cells-squamous epithelium interaction.
authors.affiliation: Department of Pathology, Albert Einstein College of Medicine and Montefiore Medical Center, 111 E210th St, North 4 Silver Zone, Bronx, NY 10467, USA.
authors.forename: Samson W
authors.initials: SW
authors.lastname: Fine
authors.forename: Maomi
authors.initials: M
authors.lastname: Li
mesh_terms: D014408:Biomarkers, Tumor / Q000378:metabolism; D064032:Calbindin 2; D002452:Cell Count; D005260:Female; D016586:Granular Cell Tumor / Q000209:etiology / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D007265:Inhibins / Q000378:metabolism*; D009375:Neoplasms, Glandular and Epithelial; D064030:S100 Calcium Binding Protein G / Q000378:metabolism*; D009418:S100 Proteins / Q000378:metabolism; D012583:Schwann Cells / Q000473:pathology
chemical_list: D014408:Biomarkers, Tumor; C576764:CALB2 protein, human; D064032:Calbindin 2; D064030:S100 Calcium Binding Protein G; D009418:S100 Proteins; C094377:inhibin-alpha subunit; D007265:Inhibins