The thymic cysts are benign tumours of the thyme-pharyngeal canal, usually
located in the cervico-mediastinal region.
The authors report the case of a large thymic cyst with an ectopic right pa
racardiac location compressing the right heart chambers. It was a chance fi
nding on chest X-ray of an asymptomatic 21 year old man.
Though suggestive of a pericardial cyst in view of its position, curative s
urgical ablation allowed confirmation of the diagnosis at anatomo-pathologi
cal examination.