Fig. 3

Endoscopic examination of nasopharyngeal necrosis. Nasopharyngeal necrosis is shown under endoscopic examination (arrows). a The necrosis is located in the roof, posterior, and left wall with obvious mucosa ulcer. Sequestra and necrotic bones can also be seen in the nasopharyngeal cavity. b The nasopharyngeal cavity is covered with yellow to black purulent secretion with necrosis located in the roof, posterior, and right lateral wall of the nasopharynx