Recurrent laryngeal neuropathy secondary to nerve compression by melanomas - case report

Abstract

Recurrent laryngeal neuropathy (RLN) etiology can be acquired, iatrogenic or idiopathic. There are no previous reports of RLN caused by recurrent laryngeal nerve compression by melanomas. This report describes a horse presenting severe dyspnea and progressive weight loss. Physical exam demonstrated tachycardia, tachypnea, inspiratory dyspnea at rest, neck extension and mydriasis. Temporary tracheotomy was performed and videoendoscopic examination diagnosed grade IV laryngeal paralysis. The animal came suddenly to death by suppurative bacterial pneumonia. At necropsy, it was possible to observe multiple melanotic epithelioid melanoma nodules compressing the recurrent laryngeal nerve, alongside with lung and parotid metastasis. This finding emphasizes the importance of establishing a differential diagnosis for tumor mass compression in the etiology of RLN, especially melanomas in gray horses, with or without cutaneous manifestations of masses.