Thornwaldt's cyst and surgery with powered instrumentation.

Thornwaldt's cyst is a relatively rare lesion located in the posterior wall of the nasopharynx. Most are small and asymptomatic whereas some cause nasal obstruction, postnasal drip, occipital headache or Eustachian tube dysfunction. Nasal endoscopy is the easiest way to visualize this during a routine ENT examination. If in any doubt, MRI is the most sensitive method for detecting and evaluating its size, its anatomic relationships and its content. When the lesion is large, symptomatic or close to the Eustachian tube torus, surgery by marsupialization is the treatment option. For small lesions, the endonasal approach is recommended but for large lesions, a transoral retrovelar approach using a 70 degree telescope is the method of choice. The powered instrumentation with a specific blade for adenoid resection permits large marsupialization with minimal trauma and bleeding and excellent postoperative results. The authors present their experience and review the relevant literature.