Congenital middle ear cholesteatoma: need for early recognition--role of computed tomography scan.

Background: Congenital cholesteatoma (CC) of middle ear is a rare entity that may go undiagnosed for years. Patients with CC who are diagnosed at a later stage of disease have poor outcome. There is controversy regarding the best way to delineate CC preoperatively. More specifically, the need to obtain preoperative computed tomography (CT) scan in all cases of CC is debated.
Objectives: This study was conducted to determine factors that may influence the outcome of surgery in CC as well as the value of obtaining preoperative CT scan in CC.
Method: A retrospective chart review of all patients with a diagnosis of middle ear cholesteatoma operated on between 1994 and 2000 was carried out. Patients with CC were identified using the criteria proposed by Levenson and Parisier.
Results: Thirty-five patients with CC were identified. In 30 (86%) patients, the diagnosis was made during ear examination and the remaining five (14%) patients were diagnosed during myringotomies. Preoperative CT scans were available in 17 patients. The findings on CT scans were classified into four categories based on the ossicular chain and mastoid septae status as well as the presence or absence of middle ear and mastoid opacification. Intraoperatively, 22 (63%) patients were found to have extensive cholesteatomas with or without extension beyond the mesotympanum. Eleven of these 22 patients had ossicular chain erosion and five were later found to have recidivism. Preoperative CT scan accurately predicted the extent of the cholesteatoma seen during surgery in 14/17 (82%) and ossicular chain status in 15/17 (88%), while micro-otoscopy predicted the extent of the existing pathology in only 10/35 (29%). Intraoperative location and size of CC influenced the type of surgical approach, status of ossicular chain, postoperative hearing level and rate of recidivism.
Conclusions: Children still present with late stage CC. Micro-otoscopy is insufficient to clearly delineate the extension of CC. Preoperative CT scan is essential in defining the extent of existing pathology. The intraoperative CC size and location influence the outcome of surgery. Early surgical intervention and long-term follow-up are essential.