Iatrogenic cholesteatoma originating from a misplaced tympanomeatal flap during tympanoplasty: a series of five patients

Purpose To report our experience of a sequence of events that resulted in an iatrogenic cholesteatoma originating from the external auditory canal (EAC) years after tympanoplasty that had included a tympanomeatal flap. Methods Data on the presentation and pathogenesis of iatrogenic cholesteatomas arising from misplaced tympanomeatal flaps during tympanoplasty without mastoidectomy were retrieved from the patients’ medical records and analyzed. Results Five patients were identified with cholesteatomas involving the EAC. They all had recurrent ear infections and varying degrees of conductive hearing loss. Each patient’s past surgical history included one or more tympanoplasties in which an ipsilateral tympanomeatal flap had been raised. None had undergone a mastoidectomy. Two patients presented with small cholesteatomas that had developed over an average of 6.5 years after surgery. Three patients had large cholesteatomas that had developed over an average of 33.7 years after surgery. Clinical presentations and imaging studies suggested a misplaced tympanomeatal flap as the most likely source of cholesteatoma. Conclusion Tympanomeatal flap misplacement may cause iatrogenic cholesteatoma formation originating from the EAC during tympanoplasty even without mastoidectomy. These cholesteatomas can grow substantially before becoming symptomatic as they extend to and through the mastoid. They may not affect the sound conduction system until late in the course of the disease. Meticulous replacement of tympanomeatal flaps and exercising a high index of suspicion postoperatively can reduce the incidence of this complication.