Nasopharyngeal amelanotic melanoma in cat: A case report

Abstract

Upper airway obstruction is one of the most important respiratory diseases, which is a life-threatening emergency in cats. A 10-year-old sterilized female domestic shorthair (DSH) cat was referred to the Small Animal Teaching Hospital (SATH), Faculty of Veterinary Science, Chulalongkorn University for diagnosis and treatment. She was quiet, alert, and responsive (QAR) and had a normal appetite. The clinical signs of upper respiratory distress with stridor had been presented for more than three months. Computed tomography (CT) and radiography examination were used for diagnosis, and the results showed a soft tissue mass in the nasopharyngeal region. The morphology and position of the nasopharyngeal mass were demonstrated by retrograde rhinoscopy, which underwent a biopsy simultaneously. Histopathological examination indicated an amelanotic melanoma. Immunohistochemistry staining was positive for S-100 and negative for melan-A. The finding offers a diagnostic approach for amelanotic melanoma, an uncommon occurrence in the nasopharyngeal region.