title: Malignant Mesothelioma in the Thoracic Cavity of a Crj:CD(SD) Rat Characterized by Round Hyalinous Stroma.
abstract: Spontaneous malignant mesothelioma was found in a 104-week-old male Crj:CD(SD) rat. The tumor was scattered on the surface of the lung, heart, mediastinal pleura and thoracic wall and metastasized to the alveolar septa. Histopathologically, small flattened or cuboidal tumor cells proliferated with stroma, formed almost normal papillary structures and reacted positively to colloidal iron stain and immunohistochemical staining for mesothelin. Round hyalinous stromata were pronounced, which is a characteristic feature, and the possible reason for this is as follows; at first, a small amount of collagen fibers was formed in the center of the clusters of several tumor cells, and then the cell clusters expanded like balloons with an increase in the collagen fibers.
authors.affiliation: Kashima Laboratory, Mitsubishi Chemical Medience Corporation, 14 Sunayama, Kamisu-shi, Ibaraki 314-0255, Japan.
authors.forename: Takuya
authors.initials: T
authors.lastname: Doi
authors.forename: Yuri
authors.initials: Y
authors.lastname: Kotani
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Takahashi
authors.forename: Satomi
authors.initials: S
authors.lastname: Hashimoto
authors.forename: Naoaki
authors.initials: N
authors.lastname: Yamada
authors.forename: Hiroko
authors.initials: H
authors.lastname: Kokoshima
authors.forename: Yuki
authors.initials: Y
authors.lastname: Tomonari
authors.forename: Yumi
authors.initials: Y
authors.lastname: Wako
authors.forename: Minoru
authors.initials: M
authors.lastname: Tsuchitani