A Blount, KO Riley… - Otolaryngologic Clinics of North …, 2011 - Elsevier ... Full-size table. View Within Article. Key Points: Juvenile Nasopharyngeal Angiofibroma ... vascular arrangement of blood vessels that vary in size from capillaries to large venous channels. ... JNAs may originate from a residual vascular plexus left behind after the involution of the first ...