Pharyngeal pouch and cleft remnants in the dog and cat: a case series and review.

Remnants of the pharyngeal apparatus can (rarely) form cysts. This retrospective case series describes clinical and histologic findings of such lesions. Clinical and histology databases were searched for cases of pharyngeal remnants. Eight patients were diagnosed with cysts located subcutaneously in the head and neck, adjacent to the submandibular salivary gland, near the thyroid, and in the mediastinum. Cyst linings included ciliated epithelium, and surgical excision was curative. Knowledge of pharyngeal development is useful for their characterization. Clinicians should consider pharyngeal remnants as differentials for cystic lesions in small animals.