Cholesteatoma behind a normal tympanic membrane after trauma (Blast)

One of theories concerning the origins of cholesteatoma, is the barotraumatic etiology. It suggests blast perforation of the tympanic membrane, and secondary implantation of epithelium in the tympanic cavity, as a cause of middle ear cholesteatoma. We report a case of cholesteatoma after spontaneous healing of a tympanic membrane perforation by blast, and revue the literature about this etiology of cholesteatoma.

We report the case of a 38 year-old man with a history of bilateral blast injury trauma 4 years earlier. The blast caused a bilateral tympanic perforation. The right tympanic membrane healed spontaneously and a left tympanic perforation remained. A cholesteatoma was encountered on the right side, behind a scared tympanic membrane, during preoperative imaging study for surgery for the left side. The literature describes an incidence of 3 to 12% cholesteatoma after blast injury, rarely behind a closed tympanic membrane. We discuss the best imaging methods to detect cholesteatoma in these cases.

After a blast injury, a cholesteatoma may arise behind a spontaneously healed tympanic membrane. For this reason, spontaneous healing of the perforation does not mean the end of the follow-up. It is essential to plan a follow-up with imaging test one year after the blast trauma. We consider that in cases of traumatic tympanic membrane perforations due to blast injury with spontaneous healing of the perforation, HRCT scan offers a better diagnostic performance and a higher spatial resolution for cholesteatoma detection (as it relates to an aerated mastoid and tympanic cavity) than DW MRI. Furthermore, it is available in the great majority of health centers.