Intravascular papillary endothelial hyperplasia (Masson lesion) of the hypopharynx and larynx.

Masson lesion is characterized by a benign intravascular papillary hyperplasia and subsequent thrombosis. Clinically, this lesion can be misdiagnosed as mucocele, hemangioma, Kaposi sarcoma, angiosarcoma, pyogenic granuloma, and several other lesions. In this article, we report a case of intravascular papillary endothelial hyperplasia of the hypopharynx and larynx, which caused dysphagia in an 18-year-old female patient. The lesion was excised entirely via a lateral pharyngotomy approach. We discuss the clinical and histopathologic features, differential diagnosis, and treatment of this uncommon entity.