Early x-ray diagnosis of occult infiltrating nasopharyngeal carcinoma.

The occult type of nasopharyngeal carcinoma (NPC) accounts for 30% of all nasopharyngeal carcinomas. The occult NPC is clinically difficult to visualize, because the tumor infiltrates and grows in the submucosa. It then metastasizes to the skull base or draining lymph nodes. When the NPC is finally diagnosed, the prognosis is poor. Three refined x-ray techniques are evaluated for their utilization in earlier diagnosis of the occult NPC: thin section tomography, nasopharyngography, and Eustachian tube function studies. In a consecutive series of 50 patients, these techniques detected 12 infiltrating carcinomas not visible on clinical examination. Five of these patients also had initially negative blind biopsies. Patients having diplopia, facial numbness, cervical adenopathy, and chronic serous otitis media are highly suspect for NPC. The described x-ray techniques, that are safe and noninvasive, can detect these occult infiltrative tumors earlier than clinical examination. Earlier detection and treatment of NPC has resulted in a significant increased cure rate.