[Piriform sinus fistulas as rare hypopharyngeal abnormalities, diagnosis and therapy].

We report on the history, clinical findings, diagnostic examinations and the therapy of three patients with a left piriform sinus fistula, probably a fourth pharyngeal pouch. Our patients show recurrent inflammation and abscesses of the left lateral neck. X-ray (gastrografin swallow) showed the fistula originating from the floor of the left piriform sinus. CT-scan was helpful in the previously operated area, although the fistula could be shown by ultrasonic examination. Recurrent abscesses of the lateral neck may be caused by sinus piriform fistula. It is important to search for this rare malformation of the lateral neck.