title: Mixed thymoma in a cow.
abstract: A neoplastic mass measuring 25 x 8 x 3 cm was found in the mediastinum of a 10-year-old Holstein cow. The neoplasm was encapsulated, multilobulated, and cystic. Several firm adhesions were present between the neoplasm and the right cranial lung lobe and the ipsilateral side of the pericardial sac. Under microscopic examination, the neoplasm was characterized by solid sheets of spindle epithelial cells (pancytokeratin and high molecular weight cytokeratin positive) subdivided by fibrous trabeculae. Numerous individualized or small aggregates of mature T-cell (CD3 positive) lymphocytes were scattered throughout the neoplastic cell population. Based on the gross, histologic, and immunohistochemical findings, the neoplasm was diagnosed as a mixed thymoma.
authors.affiliation: Programa de Patologia Molecular, Faculdade de Medicina, Universidade de Brasília, Asa Norte, 70910-900 Brasília, DF, Brazil.
authors.forename: Roselene
authors.initials: R
authors.lastname: Ecco
authors.forename: Ingeborg M
authors.initials: IM
authors.lastname: Langohr
authors.forename: Erno
authors.initials: E
authors.lastname: Türy
authors.forename: Helvécio L
authors.initials: HL
authors.lastname: Santos Júnior
authors.forename: Gabriel C
authors.initials: GC
authors.lastname: Jacobina
mesh_terms: D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000473:pathology*; D017809:Fatal Outcome; D005260:Female; D007150:Immunohistochemistry / Q000662:veterinary; D008479:Mediastinal Neoplasms / Q000473:pathology / Q000601:surgery / Q000662:veterinary*; D013945:Thymoma / Q000473:pathology / Q000601:surgery / Q000662:veterinary*