Thymoma in a dog with a part of granular cell proliferation and concurrent lymphoma cells.
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.
Fukuoka
Ayumi
A
Department of Veterinary Pathology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Japan.
Nakayama
Hiroyuki
H
Nakayama
Yumi
Y
Yasoshima
Akira
A
Uetsuka
Koji
K
Fujino
Yasuhito
Y
Tsujimoto
Hajime
H
Doi
Kunio
K
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*
D014408:Biomarkers, Tumor