Delayed irradiation effects on nasal epithelium in patients with nasopharyngeal carcinoma - An ultrastructural study

The ostiomeatal complex is responsible for the clearance of most sinus secr etions. To evaluate the delayed effects of irradiation, this study examined the infundibulum mucosa of 10 patients who developed sinusitis after recei ving radiotherapy for nasopharyngeal carcinoma (NPC) Pathologic findings un der the light microscope revealed an increased deposition of dense collagen ous fibers in the lamina propria. The epithelial cells also transformed int o a stratified arrangement and showed gradual reduction of cytoplasmic volu me. Ultrastructural observations detected areas of ciliary loss, intercellu lar and intracellular vacuolation, and ciliary dysmorphism. Most of these p athologic findings were observed even ina patient 23 years after irradiatio n. The results presented herein suggest that radiotherapy may cause long-te rm damage to the nasal epithelium that may be responsible for the prolonged sinusitis of irradiated NPC patients.