title: A spontaneously occurring malignant pituicytoma in a male sprague dawley rat.
abstract: Pituicytoma is an extremely rare neoplasm derived from pituicytes, which are glial cells in the posterior lobe of the pituitary gland. A malignant pituicytoma was found in the intracranial cavity of a 55-week-old male Sprague-Dawley rat. Macroscopically, the tumor was located on the sphenoid bone and involved the pituitary gland. The tumor was composed of sheets of fusiform cells with spindle- or pleomorphic-shaped nuclei and abundant eosinophilic cytoplasms. The cells were arranged in a whirling or irregular growth pattern. Some tumor cells were bizarre multinucleated giant cells with cytoplasmic eosinophilic hyaline droplets. Many tumor cells were strongly positive for vimentin and glial fibrillary acidic protein, and some cells were positive for ED-1 and S-100. These findings closely resembled those of a giant cell glioblastoma derived from the pituitary gland, suggesting anaplastic pituicytoma. From our review of the literature, we believe this is the first report of a spontaneous malignant pituicytoma in a rodent.
authors.affiliation: Department of Toxicological Research, Research Laboratories, Maruho Co., Ltd., 93 Awata-cho, Chudoji, Shimogyo-ku, Kyoto, Kyoto 600-8815, Japan.
authors.forename: Takayasu
authors.initials: T
authors.lastname: Moroki
authors.affiliation: Department of Toxicological Research, Research Laboratories, Maruho Co., Ltd., 93 Awata-cho, Chudoji, Shimogyo-ku, Kyoto, Kyoto 600-8815, Japan.
authors.forename: Tomo
authors.initials: T
authors.lastname: Sasaki
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 Toxicological Research, Research Laboratories, Maruho Co., Ltd., 93 Awata-cho, Chudoji, Shimogyo-ku, Kyoto, Kyoto 600-8815, Japan.
authors.forename: Takaaki
authors.initials: T
authors.lastname: Doi
keywords: giant cells; glioblastoma; immunohistochemistry; pituicytoma; pituitary gland; rats