title: A spontaneously occurring malignant ovarian Sertoli cell tumor in a young Sprague Dawley rat.
abstract: Primary ovarian tumors are generally uncommon in rats used in toxicologic studies. A malignant Sertoli cell tumor was present in the ovary of a 19-week-old female Sprague Dawley rat. Macroscopically, the mass was white and firm, 10 × 13 × 17 mm in size, and located in the right ovary. Histopathologically, the mass was composed of nests of pleomorphic cells, which formed seminiferous-like tubules separated by a thin fibrovascular stroma. The tubules were lined by tumor cells, which had basally located nuclei and abundant eosinophilic and vacuolated cytoplasm. In some areas, the tumor cells were arranged in a retiform growth pattern, mimicking a rete testis/ovarii. Disseminated metastases to the surfaces of the mesentery, spleen and liver were also present. Immunohistochemically, many tumor cells were strongly positive for vimentin, estrogen receptor α and Ki 67. Some tumor cells were positive for pancytokeratin and inhibin α. These findings closely resemble those of an ovarian-derived human malignant Sertoli cell tumor. From our review of the literature, we believe this is the first report of a spontaneous malignant Sertoli cell tumor in the ovary of a young laboratory rat. This case might provide useful historical control information for rat toxicity studies.
authors.affiliation: Department of Pathology II, Kansai Medical University, 2-5-1 Shin-machi, Hirakata, Osaka 573-1010, Japan; Division of Diagnostic Cytopathology and Histopathology, Kansai Medical University Takii Hospital, Fumizono 10-15, Moriguchi, Osaka 570-8507, Japan.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Kinoshita
authors.affiliation: Department of Pathology II, Kansai Medical University, 2-5-1 Shin-machi, Hirakata, Osaka 573-1010, Japan.
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Yoshizawa
authors.affiliation: Department of Pathology II, Kansai Medical University, 2-5-1 Shin-machi, Hirakata, Osaka 573-1010, Japan.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Emoto
authors.affiliation: Department of Pathology II, Kansai Medical University, 2-5-1 Shin-machi, Hirakata, Osaka 573-1010, Japan.
authors.forename: Michiko
authors.initials: M
authors.lastname: Yuki
authors.affiliation: Department of Pathology II, Kansai Medical University, 2-5-1 Shin-machi, Hirakata, Osaka 573-1010, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Yuri
authors.affiliation: Division of Diagnostic Cytopathology and Histopathology, Kansai Medical University Takii Hospital, Fumizono 10-15, Moriguchi, Osaka 570-8507, Japan.
authors.forename: Nobuaki
authors.initials: N
authors.lastname: Shikata
authors.affiliation: Cellular & Molecular Pathology Branch, National Institute of Environmental Health Sciences, 111 T.W. Alexander Drive, Research Triangle Park, NC 27709, USA.
authors.forename: Susan A
authors.initials: SA
authors.lastname: Elmore
authors.affiliation: Department of Pathology II, Kansai Medical University, 2-5-1 Shin-machi, Hirakata, Osaka 573-1010, Japan.
authors.forename: Airo
authors.initials: A
authors.lastname: Tsubura
keywords: Sertoli cell; immunohistochemistry; malignant tumor; ovary; spontaneous; young rat