Head and Neck Radiology History: 51 year old man presented with increasing neck swelling and stridor. click for a larger image CT Findings: There is a cystic mass beginning in the left paraglottic space extending superiorly and laterally through the thyrohyoid membrane. The wall is thick and enhances. There is injection of the adjacent fat. Diagnosis: Laryngopyocoele. Discussion: Laryngoceles are due to relative obstruction of the appendix or saccule of the laryngeal ventricle in the paraglottic space. The saccule enlarges producing a submucosal mass. The lesion can be air-filled (laryngocele), fluid filled (laryngeal mucocele), or pus filled (laryngopyocele). If the laryngocele is confined to the larynx it is an internal laryngocele. A combined or mixed lesion has components both inside and outside the larynx as in the present case. External laryngoceles appear to have only an extralaryngeal component, but always have an intralaryngeal component which is simply not evident on imaging. Although the laryngocele itself is a benign lesion, a tumor in the ventricle should be excluded. Thus, these patients require endoscopy. References: Curtin, HD. "Larynx." In Head and Neck Imaging, Som and Curtin, eds. St. Louis: Mosby-Yearbook. pp 665-671. Submitted by: Lawrence M. Davis, MD TOP