title: Spontaneous Basal cell carcinoma of the submandibular gland in a rat.
abstract: At necropsy, a white nodule (about 5 × 3 mm in size) was observed in the right submandibular gland of a 10-week-old female GALAS rat. Histopathologically, oval to spindle-shaped and pale basophilic tumor cells proliferated closely, and formed variably sized foci. The nodule partially spread into or invaded the surrounding normal tissue, and necrotic foci were recognized in the tumor. Immunohistochemically, the nuclei of the tumor cells showed a diffusely positive reaction for p63, and the cytoplasm showed a diffusely positive reaction for cytokeratin and negative reaction for αSMA, vimentin, desmin and S-100. Many tumor cells were positive for PCNA. Ultrastructurally, the tumor cells contained many tonofilaments in the cytoplasm and a few desmosomes at the intercellular portion. Based on these findings, the tumor was diagnosed as a basal cell carcinoma originating from the duct in the rat submandibular gland.
authors.affiliation: Sugi Institute of Biological Science Co., Ltd., 10221 Kobuchisawa-cho, Hokuto-shi, Yamanashi 408-0044, Japan.
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Kobayashi
authors.forename: Hiro
authors.initials: H
authors.lastname: Eda
authors.forename: Emiko
authors.initials: E
authors.lastname: Kajino
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Tate
authors.forename: Masami
authors.initials: M
authors.lastname: Hiruma
authors.forename: Yasuki
authors.initials: Y
authors.lastname: Akie
authors.forename: Akemi
authors.initials: A
authors.lastname: Saito
authors.forename: Toshihito
authors.initials: T
authors.lastname: Kadota