Lymphatic, venous, and mixed lymphovenous malformations are low-flow lesions that are present at birth and grow proportionately with the patient. We describe an unusual presentation of a lymphovenous malformation in an adult. A 19-year-old man presented to the emergency department with complaints of recent upper respiratory tract symptoms, increasing left-sided sore throat, voice change, odynophagia, dysphagia, and occasional subjective fevers and blood-tinged sputum. Examination revealed the presence of a left peritonsillar bulge consistent with a peritonsillar abscess; however, findings on needle aspiration were negative. The patient was admitted for intravenous steroid and antibiotic therapy. Within 24 hours, his airway became compromised, and he underwent an awake tracheotomy and biopsy, which showed a lymphovenous malformation. Magnetic resonance imaging the following day revealed a large, poorly circumscribed, heterogeneous left parapharyngeal mass consistent with a vascular malformation. With continuation of the steroids and antibiotics, the lesion regressed, and the patient was subsequently decannulated. At the 1-year follow-up, he exhibited no clinical symptoms, and he was in good health off steroids.