title: Thymoma in a dog with a part of granular cell proliferation and concurrent lymphoma cells.
abstract: A 12-year-old male Shiba dog showed anemia and the swelling of systemic lymph nodes. X-ray and post mortal examinations revealed a anterior mediastinal mass. Histologically, the tumor mass consisted of four different elements; cord-like proliferation of cuboidal epithelial cells, tubular or cystic structures lined with ciliated epithelial cells, proliferation of large round-shaped epithelial cells with PAS-slightly positive granular cytoplasm, and diffuse proliferation of neoplastic lymphocytes. Epithelial cells in cord-like or cystic structures were strongly positive for cytokeratin. Granular or foamy cells were negative for all markers examined and had myelin-like bodies in the cytoplasm by electron microscopy. The neoplastic lymphocytes in the tumor mass were considered being derived from concurrent multicentric lymphoma. Based on these findings, the present case was diagnosed as thymoma with a part of granular cell proliferation and concurrent lymphoma cells.
authors.affiliation: Department of Veterinary Pathology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Japan.
authors.forename: Ayumi
authors.initials: A
authors.lastname: Fukuoka
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Nakayama
authors.forename: Yumi
authors.initials: Y
authors.lastname: Nakayama
authors.forename: Akira
authors.initials: A
authors.lastname: Yasoshima
authors.forename: Koji
authors.initials: K
authors.lastname: Uetsuka
authors.forename: Yasuhito
authors.initials: Y
authors.lastname: Fujino
authors.forename: Hajime
authors.initials: H
authors.lastname: Tsujimoto
authors.forename: Kunio
authors.initials: K
authors.lastname: Doi
mesh_terms: D000818:Animals; D014408:Biomarkers, Tumor / Q000032:analysis; D004283:Dog Diseases / Q000473:pathology*; D004285:Dogs; D007150:Immunohistochemistry / Q000662:veterinary; D008198:Lymph Nodes / Q000473:pathology; D008223:Lymphoma / Q000473:pathology / Q000662:veterinary*; D008297:Male; D009378:Neoplasms, Multiple Primary / Q000737:chemistry / Q000473:pathology*; D013945:Thymoma / Q000473:pathology / Q000662:veterinary*; D013953:Thymus Neoplasms / Q000473:pathology / Q000662:veterinary*
chemical_list: D014408:Biomarkers, Tumor