Diagnosis and management of a laryngeal cyst in a domestic shorthair cat

Abstract

Case summary: A 7-year-old male neutered domestic shorthair cat was presented with a 3-month history of dyspnea when exercising and increased respiratory noise when purring. Initial radiographs identified a suspected laryngeal mass. Point-of-care ultrasound found a fluid-filled structure on the larynx, which was drained percutaneously. The cat initially recovered well but, due to recurrence of clinical signs, a CT scan was performed, which confirmed the presence of a laryngeal cyst that was subsequently surgically resected. Histopathological analysis was consistent with a suspected thyroglossal cyst.

Relevance and novel information: This is only the second report of a laryngeal cyst in the cat. While malignant laryngeal disease may be more prevalent in the cat, benign differentials should be considered as treatment could be curative, as was observed in this case.

Keywords: Respiratory; cyst; dyspnea; larynx.

Figure 1

A round, homogeneously soft tissue opaque structure (ie, laryngeal cyst) was appreciated within the larynx on a right lateral radiograph of the head and neck region of the patient. Image courtesy of the referring veterinarian

Figure 2

Photograph of the oral cavity and laryngeal area of the sedated cat demonstrating a large mass (ie, laryngeal cyst) protruding from the left side of the larynx, displacing the arytenoids laterally to the right

Figure 3

Echolaryngography of the anesthetized cat demonstrating a laryngeal cyst, as outlined by the yellow arrows

Figure 4

Post-contrast transverse CT image displayed on a soft tissue window width/window level at the level of the first cervical vertebra. A thin-walled, centrally fluid-attenuating structure (marked with a white star) is seen within the left aspect of the larynx. The structure has a thin, contrast-enhancing peripheral rim (white arrow) and occupies more than 50% of the laryngeal lumen