Well-differentiated biphasic synovial sarcoma in the atlanto-occipital joint of a Holstein cow.
A 7-year-old Holstein cow developed a large cystic mass in the region between the atlantoaxis and larynx. The mass extended to the synovium in the atlanto-occipital joint. Many villous projections were present on the inner surface of the tumor tissue, and irregular clefts were formed in the inside. Two cell types, epithelioid-like synovioblasts and spindle cells, were present. Immunohistochemical analysis showed that the cells stained positively for cytokeratin (AE1/AE3) and vimentin. Both cells had similar fine structures ultra-structurally. Vacuoles present in the cytoplasm were full of an acid mucous substance. The tumor was diagnosed as a well-differentiated biphasic synovial sarcoma. This is the first report of a rare case of synovial sarcoma, from the viewpoint of its origin.
Oyamada
T
T
Department of Veterinary Pathology, Faculty of Veterinary Medicine and Animal Sciences, Kitasato University, 034-8628, Higashi 23-35-1, Towada City, Aomori, Japan. oyamd@vmas.kitasato-u.ac.jp
Otsuka
H
H
Kohiruimaki
M
M
Ohta
J
J
Yoshikawa
H
H
D000818:Animals; D001269:Atlanto-Occipital Joint / Q000473:pathology* / Q000648:ultrastructure; D002417:Cattle; D002418:Cattle Diseases / Q000473:pathology*; D005260:Female; D007592:Joint Diseases / Q000473:pathology / Q000662:veterinary; D011247:Pregnancy; D013584:Sarcoma, Synovial / Q000473:pathology / Q000648:ultrastructure / Q000662:veterinary*