title: Salivary mucocele in a laboratory beagle.
abstract: The histologic characteristics of a salivary mucocele in a beagle used in a toxicity study are described in this report. A pale yellowish cyst under the mandibular skin containing frothy mucus was observed at necropsy. Microscopically, numerous villous projections arose from the internal surface of the cyst and were lined by stratified epithelial-like macrophages, which were immunopositive for macrophage scavenger receptor A. A ruptured sublingual interlobar duct connected to the lumen was observed near the cyst. Luminal amorphous material showed a positive reaction with Alcian blue and periodic acid-Schiff staining as did mucin in the sublingual gland. Ultrastructurally, the epithelial-like macrophages had numerous vacuoles containing electron-lucent material, which was presumed to be lysosomal in origin, and had pseudopods on their cell surfaces interdigitating with those on the adjacent cells. This case report helps to understand the diversity of the background findings in beagles used in toxicity studies.
authors.affiliation: Development Research Center, Takeda Pharmaceutical Company Limited, 2-17-85 Jusohonmachi, Yodogawa-ku, Osaka 532-8686, Japan.
authors.forename: Hironobu
authors.initials: H
authors.lastname: Yasuno
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Nagai
authors.forename: Yoshimasa
authors.initials: Y
authors.lastname: Ishimura
authors.forename: Takeshi
authors.initials: T
authors.lastname: Watanabe
authors.forename: Hideki
authors.initials: H
authors.lastname: Yamasaki
authors.forename: Hisashi
authors.initials: H
authors.lastname: Anayama
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Takai
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Yamauchi
authors.forename: Yoko
authors.initials: Y
authors.lastname: Hara
authors.forename: Fumi
authors.initials: F
authors.lastname: Murai
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Kandori