Cutaneous Hybrid Cyst in a Sprague-Dawley Rat

Kyohei Yasuno; Haruka Sakashita; Saori Araki; Ryosuke Kobayashi; Yosuke Sakurada; Mariko Shirota; Junichi Kamiie; Kinji Shirota

doi:10.1293/tox.25.175

Case Reports

Cutaneous Hybrid Cyst in a Sprague-Dawley Rat

Kyohei Yasuno, Haruka Sakashita, Saori Araki, Ryosuke Kobayashi, Yosuke Sakurada, Mariko Shirota, Junichi Kamiie, Kinji Shirota

Author information

Kyohei Yasuno
Research Institute of Biosciences, School of Veterinary Medicine, Azabu University, 1-17-71 Fuchinobe, Chuo-ku, Sagamihara, Kanagawa 252-5201, Japan
Haruka Sakashita
Research Institute of Biosciences, School of Veterinary Medicine, Azabu University, 1-17-71 Fuchinobe, Chuo-ku, Sagamihara, Kanagawa 252-5201, Japan
Saori Araki
Research Institute of Biosciences, School of Veterinary Medicine, Azabu University, 1-17-71 Fuchinobe, Chuo-ku, Sagamihara, Kanagawa 252-5201, Japan
Ryosuke Kobayashi
Research Institute of Biosciences, School of Veterinary Medicine, Azabu University, 1-17-71 Fuchinobe, Chuo-ku, Sagamihara, Kanagawa 252-5201, Japan
Yosuke Sakurada
Safety Assessment II, Safety & Bioscience Division, Development Research Laboratories, Kyorin Pharmaceutical Co., Ltd., 1848 Nogi, Nogi-machi, Shimotsuga-gun, Tochigi 329-0114, Japan
Mariko Shirota
Laboratory of Comparative Toxicology, School of Veterinary Medicine, Azabu University, 1-17-71 Fuchinobe, Chuo-ku, Sagamihara, Kanagawa 252-5201, Japan
Junichi Kamiie
Laboratory of Veterinary Pathology, School of Veterinary Medicine, Azabu University, 1-17-71 Fuchinobe, Chuo-ku, Sagamihara, Kanagawa 252-5201, Japan
Kinji Shirota
Research Institute of Biosciences, School of Veterinary Medicine, Azabu University, 1-17-71 Fuchinobe, Chuo-ku, Sagamihara, Kanagawa 252-5201, Japan
Laboratory of Veterinary Pathology, School of Veterinary Medicine, Azabu University, 1-17-71 Fuchinobe, Chuo-ku, Sagamihara, Kanagawa 252-5201, Japan

Keywords: kin, hybrid cyst, epidermal inclusion cyst, cytokeratin, Sprague-Dawley rat

JOURNAL FREE ACCESS

2012 Volume 25 Issue 2 Pages 175-178

DOI https://doi.org/10.1293/tox.25.175

Details

Abstract

This report describes a spontaneous hybrid cyst in a Sprague-Dawley (SD) rat. A 52-week-old, male SD rat had a cutaneous cyst on the left mystacial pad. Histologically, the cyst wall showed infundibular differentiation with keratohyalin granules in the granular layer and matrical differentiation comprising basaloid epithelial cells with trichohyalin granules. The cyst cavity was filled with lamellar, flaky keratin and aggregates of shadow cells. Immunohistochemically, the infundibular-type epithelium was positive for cytokeratin (CK) AE1/AE3, CK KL1 and CK14 but negative for CK15, whereas the matrical-type epithelium was negative for all four CK isoforms examined. These immunohistochemical properties of the infundibular- and matrical-type epithelia were similar to those of the infundibulum and inferior segment of normal hair follicles, respectively. Based on these findings, the cyst was diagnosed as a hybrid cyst, comprising more than one type of cyst arising from various parts of the pilosebaceous unit.

Corresponding author

Register with J-STAGE for free!