Epidermoid Cyst of the Soft Palate in a Geriatric Cat: A Case Report

Epidermoid cysts within the oral cavity are rare in cats. Here, we report the clinical, imaging, surgical, and histopathological findings of an epidermoid cyst originating from the soft palate of a geriatric cat. A 17-year-old neutered female domestic shorthaired cat presented with mild hypersalivation and dysphagia. Computed tomography revealed a well-circumscribed, minimally contrast-enhancing mass measuring 8.5 × 9.9 × 10.0 mm arising from the right distal soft palate. The mass protruded predominantly into the oropharynx and caused mild nasopharyngeal displacement, without evidence of bone invasion or middle ear involvement. Surgical excision was performed, and histopathological examination revealed a cyst lined with keratinizing stratified squamous epithelium containing keratinaceous debris, which was consistent with a benign epidermoid cyst. Hypersalivation and dysphagia were no longer observed after excision, although this improvement was documented for only approximately 24 h before severe gastrointestinal dysfunction and recurrent seizures developed. Although repeated oral mucosal irritation was considered a possible contributing factor, the congenital or acquired origin of the cyst could not be definitively determined. This case highlights that epidermoid cysts should be considered in the differential diagnosis of cystic lesions of the oral cavity in cats.