Laryngeal Stroboscopy and Acoustic Analyses for the Diagnosis of Intracordal Retention Cyst

Yun, Young Sun; Ko, Young Hyeh; Baek, Chung Hwan; Son, Young Ik

Abstract

BACKGROUND AND OBJECTIVES
Decrease in mucosal waves and diplophonia are known as main diagnostic criteria of vocal cysts. However, preoperative differential diagnosis of intracordal retention cyst (IRC) over vocal polyp and/or edema is not infrequently challenging even with those criteria. Authors aimed to evaluate the efficacy of laryngeal stroboscopy and acoustic analyses for the proper diagnosis of IRC. MATERIALS AND METHOD: We reviewed medical records of 30 patients who were initially diagnosed as having IRC either through laryngeal endoscopy or stroboscopy. Endoscopic and/or stroboscopic findings, acoustic and perceptual parameters were analyzed in comparison to the final pathologic diagnosis. RESULTS: Only 70% of the subjects were correctly diagnosed with laryngeal stroboscopy, which suggested the need of reconsideration of current diagnostic criteria. Decrease in mucosal waves was a frequently observable but not a specific finding confined to IRC. Diplophonia was neither a common nor a specific finding of IRC. Acoustic evaluation was not helpful for the differential diagnosis of IRC over vocal polyp. Hemorrhagic changes around the lesion were observed in some of vocal polyps but not in any of IRC. CONCLUSION: Decreased or absent mucosal wave is one of the characteristics of IRC, but is a not absolute criterion for the differential diagnosis between IRC and vocal polyp. Diplophonia and other acoustic parameters are not helpful for the differential diagnosis of those lesions. A careful endoscopic or stroboscopic evaluation of general contour, mucosal change and any surrounding hemorrhage will help in the proper differential diagnosis of IRC over vocal polyp. Decrease in mucosal waves will also help the diagnosis of IRC but not when it is overemphasized as an absolute criterion.