Spontaneous ovarian choriocarcinoma in a young ICR mouse

• Published in: Journal of Toxicologic Pathology Vol. 34; no. 1; pp. 123 - 125
• Main Authors: Mizukawa, Mao, Sato, Hiroko, Nishikawa, Satomi, Kashimura, Akane, Nishina, Hironobu, Sakairi, Tetsuya
• Format: Journal Article
• Language: English
• Published: Japan JAPANESE SOCIETY OF TOXICOLOGIC PATHOLOGY 01.01.2021; Japan Science and Technology Agency; Japanese Society of Toxicologic Pathology
• Subjects: Blood plasma; Case Report; Choriocarcinoma; CrlCD1 (ICR) mouse; Cytoplasm; Erythrocytes; germ cell tumor; Giant cells; Histopathology; Lesions; Leukocytes (eosinophilic); non-gestational origin; Nuclei; Oral administration; Organs; ovarian choriocarcinoma; Ovaries; Reproductive organs; spontaneous lesion; Tumor cells; Tumors; CrlCD1 (ICR) mouse; ovarian choriocarcinoma; spontaneous lesion; germ cell tumor; non-gestational origin
• ISSN: 0914-9198; 1881-915X; 1347-7404
• DOI: 10.1293/tox.2020-0062

This paper describes the spontaneous ovarian choriocarcinoma observed in a young female Crl:CD1 (ICR) mouse. The mouse was sacrificed at 8 weeks of age after oral administration of a compound for 2 weeks. The left ovary was found to be cystically enlarged with dark red hemorrhaging. The cystic mass contained abundant blood plasma and erythrocytes. At the peripheral regions of the mass, large pleomorphic tumor cells with bizarre shaped nuclei were detected. Tumor cells contained a single large nucleus and abundant eosinophilic to amphophilic cytoplasm. Histopathology of the tumor cells resembled that of trophoblastic giant cells. Therefore, the observed ovarian lesion was diagnosed as a choriocarcinoma. No microscopic lesions were observed in the right ovary or other reproductive organs. Ovarian choriocarcinoma was considered to be of non-gestational origin. This is the first report of ovarian choriocarcinoma in a young ICR mouse.