Objectives/Hypothesis: The human cochlea is most commonly considered to have two and a half turns. Although the causes of cochlear hypoplasia are well described, cochlear hyperplasia is a rarer entity that is poorly understood. We describe rare anatomic cochlear malformations identified in a 4-month-old male originally referred for evaluation after a failed newborn hearing screening. The full diagnostic evaluation, imaging findings, treatment, and follow-up are described in detail. Cochleae with three turns are an uncommon malformation that is not included in current classifications schemes and may represent a distinct type of anomaly not caused by developmental arrest.
Keywords: Three cochlear turns; cochlea; cochlear malformations; conductive hearing loss; conductive hearing loss (CHL); hearing loss; hyperplasia congenital; hyperplastic; sensorineural hearing loss; sensorineural hearing loss (SNHL).
© 2015 The American Laryngological, Rhinological and Otological Society, Inc.