Dysgerminoma in an Arabian filly.
A yearling Arabian filly was referred to the Veterinary Medical Teaching Hospital with a history of weight loss, profound anemia, and peritoneal effusion. At necropsy, a large, soft, mottled tan and red neoplastic mass was at the pelvic inlet replacing the left ovary. Additional tumor nodules of various sizes were disseminated throughout the mesentery, diaphragm, and serosal surfaces of the abdominal viscera. Histologically, the neoplasm had sheets of large round to polygonal cells separated into lobules by fibrous connective tissue with multifocal areas of necrosis. Tumor cells stained strongly for alkaline phosphatase. Immunohistochemically, tumor cells expressed vimentin and were negative for cytokeratin. Ultrastructurally, the neoplastic cells had a characteristic nucleolus with an elaborate reticular nucleolonema in an irregular configuration. This is the first in-depth detailed report of this very rare germ cell tumor of the ovary in horses.
Department of Pathobiology, College of Veterinary Medicine, University of Florida, Gainesville 32610, USA.
A M
AM
Chandra
J C
JC
Woodard
A M
AM
Merritt
D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D002466:Cell Nucleolus / Q000648:ultrastructure; D003896:Desmosomes / Q000648:ultrastructure; D004407:Dysgerminoma / Q000378:metabolism / Q000473:pathology / Q000662:veterinary*; D005260:Female; D006734:Horse Diseases / Q000378:metabolism / Q000473:pathology*; D006736:Horses; D008854:Microscopy, Electron / Q000662:veterinary; D015388:Organelles / Q000648:ultrastructure; D010051:Ovarian Neoplasms / Q000378:metabolism / Q000473:pathology / Q000662:veterinary*
D000469:Alkaline Phosphatase