title: Mixed germ cell tumor with embryonal carcinoma, choriocarcinoma, and epithelioid trophoblastic tumor in the ovary of a cynomolgus monkey.
abstract: A seven-year-old female cynomolgus monkey had a mass in the left ovary with metastasis to the lung and the right ovary. The mass of these organs showed three different characteristics, and its immunohistochemical profiles were consistent with embryonal carcinoma (EC), choriocarcinoma (CC), and epithelioid trophoblastic tumor (ETT). The EC was characterized with sheets and glandlike structures with large pleomorphic, single-nucleated epithelial cells that were immunohistochemically positive for α-fetoprotein, octamer-4, and CD30, and with multinucleated giant cells resembling syncytiotrophoblasts. The CC also represented biphasic proliferation of the cytotrophoblast positive for cytokeratin 7 (CK7), which showed negative immunoreactivity for all three of the above antibodies, and it was syncytiotrophoblast positive for human chorionic gonadotropin. The ETT showed numerous floating cells in an abundant eosinophilic extracellular matrix with vacuolated or eosinophilic cytoplasm and was immunohistochemically positive for CK7, p63, and α-inhibin, which features nodule or cordlike structures. Collectively, this neoplasm was identified as a mixed germ cell tumor with EC, CC, and ETT. To our knowledge, this is the first report of EC in nonhuman primates as a component of mixed germ cell tumor.
authors.affiliation: Daiichi-Sankyo Co., Ltd., Medicinal Safety Research Laboratories, Tokyo, Japan. yokouchi.yusuke.uw@daiichisankyo.co.jp
authors.forename: Y
authors.initials: Y
authors.lastname: Yokouchi
authors.forename: M
authors.initials: M
authors.lastname: Imaoka
authors.forename: A
authors.initials: A
authors.lastname: Sayama
authors.forename: A
authors.initials: A
authors.lastname: Sanbuissho
mesh_terms: D000818:Animals; D018236:Carcinoma, Embryonal / Q000473:pathology*; D002822:Choriocarcinoma / Q000473:pathology*; D015622:Epithelioid Cells / Q000473:pathology*; D005260:Female; D007265:Inhibins / Q000378:metabolism; D053552:Keratin-7 / Q000378:metabolism; D008252:Macaca fascicularis; D009362:Neoplasm Metastasis / Q000473:pathology; D010053:Ovary / Q000473:pathology*; D014328:Trophoblastic Neoplasms / Q000473:pathology*; D014327:Trophoblasts / Q000473:pathology; D000509:alpha-Fetoproteins / Q000378:metabolism
chemical_list: D053552:Keratin-7; D000509:alpha-Fetoproteins; C094377:inhibin-alpha subunit; D007265:Inhibins