title: C-cell adenoma containing variously sized thyroid follicles in a horse.
abstract: A thyroid gland tumor, showing unusual histology, was identified in a 13-year-old male Andalusian horse. Microscopically, the tumor consisted of neoplastic proliferation of C-cell (parafollicular cell) with cytoplasmic fine granules, containing diffusely distributed, variously sized colloid-containing follicles. Immunohistochemically, the neoplastic C-cell were positive for calcitonin and follicleforming epithelial cells showed a positive reaction for thyroglobulin. Ultrastructurally, membrane-bound secretory granules up to 250 nm in diameter were found in the cytoplasm of the parafollicular cells, whereas the follicular epithelial cells had microvilli, junctional complex, and well-developed endoplasmic reticulum.
authors.affiliation: Department of Veterinary Pathology, College of Agriculture, Osaka Prefecture University, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Kuwamura
authors.forename: A
authors.initials: A
authors.lastname: Shirota
authors.forename: J
authors.initials: J
authors.lastname: Yamate
authors.forename: T
authors.initials: T
authors.lastname: Kotani
authors.forename: F
authors.initials: F
authors.lastname: Ohashi
authors.forename: S
authors.initials: S
authors.lastname: Sakuma
mesh_terms: D000236:Adenoma / Q000473:pathology / Q000601:surgery / Q000648:ultrastructure / Q000662:veterinary*; D000818:Animals; D002116:Calcitonin / Q000032:analysis; D003594:Cytoplasmic Granules / Q000473:pathology / Q000648:ultrastructure; D004847:Epithelial Cells / Q000473:pathology; D005500:Follow-Up Studies; D006734:Horse Diseases; D006736:Horses; D007150:Immunohistochemistry; D008297:Male; D008854:Microscopy, Electron; D013954:Thyroglobulin / Q000032:analysis; D013964:Thyroid Neoplasms / Q000473:pathology / Q000601:surgery / Q000648:ultrastructure / Q000662:veterinary*
chemical_list: D002116:Calcitonin; D013954:Thyroglobulin