Masseter and Pterygoid Muscle Hypertrophy in a Cat

A 6-year-old neutered male feline patient was presented with left sided facial swelling. A diagnosis of benign hypertrophy of the masseter and pterygoid muscles was made based on clinical, imaging, and histopathologic findings. Benign hypertrophy of masticatory muscles is an uncommon condition described in the human literature. Masseter muscle hypertrophy has been diagnosed rarely in humans with few references reporting concurrent hypertrophy of the medial and lateral pterygoid muscles. The primary inciting cause of this condition is unknown. Treatment in humans is primarily sought for cosmetic reasons with multiple treatment modalities being described including medical and surgical management. This article describes the first reported case of benign masseter and pterygoid muscle hypertrophy in the veterinary literature.