title: Testicular yolk sac tumor of myxomatous, reticular, and polyvesicular vitelline type in a newborn calf.
abstract: Yolk sac tumors (YSTs) are rare neoplasms of germ cell origin. In humans, the tumors primarily occur in the testes or ovaries, but occasionally develop at other sites. The neoplastic cells of YSTs form many histological patterns resembling embryonal structures, and the World Health Organization classification lists 11 such patterns: reticular, macrocystic, endodermal sinus, papillary, solid, glandular-alveolar, myxomatous, sarcomatoid, polyvesicular vitelline, hepatoid, and parietal. Among domestic animals, only 2 cases of YST, which were of testicular and abdominal cavity origin, have been reported in calves. In both cases, neoplastic cells had epithelial properties and disseminated metastases in the abdomen. In the present study, the enlarged testis of a newborn calf, which was subsequently diagnosed as YST and exhibited myxomatous, reticular, and polyvesicular vitelline histological patterns, is described. There was no metastasis in this case, and histological and immunohistochemical features varied from previous cases of YST.
authors.affiliation: 1Kazuya Matsuda, Department of Veterinary Pathology, School of Veterinary Medicine, Rakuno Gakuen University, 582 Bunkyodai-Midorimachi, Ebetsu, Hokkaido 069-8501, Japan. kmatsuda@rakuno.ac.jp.
authors.forename: Kanako
authors.initials: K
authors.lastname: Sakaguchi
authors.forename: Kazuya
authors.initials: K
authors.lastname: Matsuda
authors.forename: Hiromi
authors.initials: H
authors.lastname: Suzuki
authors.forename: Nao
authors.initials: N
authors.lastname: Yamamoto
authors.forename: Yumi
authors.initials: Y
authors.lastname: Kondo
authors.forename: Takaaki
authors.initials: T
authors.lastname: Ando
authors.forename: Masateru
authors.initials: M
authors.lastname: Koiwa
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Kagawa
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Taniyama
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D002417:Cattle; D002418:Cattle Diseases / Q000473:pathology*; D018240:Endodermal Sinus Tumor / Q000473:pathology / Q000662:veterinary*; D017809:Fatal Outcome; D006651:Histocytochemistry / Q000662:veterinary; D008297:Male; D009373:Neoplasms, Germ Cell and Embryonal / Q000473:pathology / Q000662:veterinary*; D013736:Testicular Neoplasms / Q000473:pathology / Q000662:veterinary*
keywords: Cattle; immunohistochemical staining; testis; yolk sac tumor