A tiny retraction of the pars flaccida may conceal an attic cholesteatoma.

Objective: The purpose of this study was to evaluate the possibility of attic cholesteatomas concealed within a tiny retraction of the pars flaccida (classification of Tos and Poulsen type I or II attic retraction) in patients with an intact pars tensa of the tympanic membrane.

Methods: The clinical records of patients with a tiny retraction of the pars flaccida and an intact pars tensa of the tympanic membrane who presented to the ear clinic of a tertiary care medical center for the first time between March 2012 and February 2015 were retrospectively reviewed. All patients who had an abnormal pars flaccida of the tympanic membrane were recommended to undergo temporal bone computed tomography (CT) scans. In cases of a soft tissue density lesion within Prussak's space, an exploratory operation was recommended.

Results: Among 1320 adult patients, 146 patients (n = 168 ears) who had a tiny attic retraction with a normal pars tensa in unilateral or bilateral ears underwent temporal bone CT scans, and 18 ears had a soft tissue density lesion within Prussak's space. Among the ears with a tiny retraction of the pars flaccida and a normal pars tensa, an attic cholesteatoma was suspected in 10.7% (n = 18 ears) of cases based on the CT scans. After exploratory operations, 2% of patients who underwent CT scans (3 out of 146 patients) and 23% of patients who had a soft tissue density lesion within Prussak's space on CT scans (3 out of 13 operations) had an attic cholesteatoma.

Conclusion: All attic retractions which are even in cases of Tos type I or II should be examined closely using endoscopy, microscopy, and, if necessary, temporal bone CT scan.