Primary external auditory canal cholesteatoma of 301 ears: a single-center study

Limited literature exists on primary external auditory canal (EAC) cholesteatoma (EACC). Here, we focus on the clinical features of this rare disease, especially the invasive patterns of lesion progression, through a large population study and present simple and practical staging. In all, 276 patients (male 99; female 177; mean age 41.3 ± 21 years; ears 301) with primary EACC were retrospectively analyzed. Stage I indicated EACC without bony lesions, stage II indicated invasion confined within EAC, stage III indicated invasion beyond the EAC involving mastoid air cells or tympanic cavity, but within the temporal bone, and stage IV indicated invasion beyond the temporal bone. In all, 41, 219, 40, and 1 ear with Stage I, II, III, and IV lesions were found, respectively. Common clinical symptoms were hearing loss (237 ears, 78.7%), otalgia (221 ears, 73.4%), and otorrhea (85 ears, 28.2%). The mean air conduction and air-bone gaps were 45.4 ± 17.9 dB HL and 24.6 ± 15 dB HL, respectively. EACCs were found to invade in all directions of the EAC, with the inferior wall (224 ears, 74.4%) > posterior wall (207 ears, 68.8%) > anterior wall (186 ears, 61.8%) > superior wall (86 ears, 28.6%) invasion; multiwall invasions (207 ears) were common; however, inward invasions into the tympanic cavity were rare. Primary EACCs occurred mostly in women and often unilaterally invaded multiple bony walls in the lower half of the EAC. The present staging reflects the patterns and severity of lesion progression and may be beneficial in treatment planning.