title: A cardiac rhabdomyoma in a Guinea pig.
abstract: A guinea pig (9-week-old) that had been placed in a control group for a pharmacological test was found to have a single nodule on the surface of the right ventricular wall. In a transverse section of the heart after fixation, a whitish mass was found that extended from the subendocardium to the subepicardium of the right ventricular wall. Histopathological examination revealed a spongy network consisting of vacuolated spaces in the myocardium of the right ventricle extending to the myocardium and subepicardium of the right atrium. The vacuolated space was PAS-positive. Immunohistochemical examinations revealed that the lesions contained striated fibers that were positive for anti-desmin and anti-myoglobin. Electron micrographs revealed the lesions resulting in affected striated muscle fibers and accumulations of many glycogen granules. Based on the findings, the lesions were diagnosed as a cardiac rhabdomyoma. This is the first report of application of immunohistochemical examinations to diagnosis of cardiac rhabdomyoma in the guinea pig.
authors.affiliation: Sugi Institute of Biological Science Co., Ltd., 10221 Kobuchisawa-cho, Hokuto, Yamanashi 408-0044, Japan.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Kobayashi
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Kobayashi
authors.forename: Uina
authors.initials: U
authors.lastname: Fukuda
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Ozeki
authors.forename: Maki
authors.initials: M
authors.lastname: Takahashi
authors.forename: Shigeru
authors.initials: S
authors.lastname: Fujioka
authors.forename: Jun-Ichi
authors.initials: J
authors.lastname: Fuchikami