Learning Objectives: Congenital cholesteatoma located in the posterior portion of the mastoid is very slowly growing and some may be treated conservatively.

Introduction: Congenital cholesteatoma of the temporal bone is a relatively rare disease. Most of them occur in the middle ear causing hearing impairment and thereby early detection. Congenital mastoidal cholesteatoma, on the other hand, prevalent in the posterior portion of the mastoid, causes no or few, mostly non-specific symptoms and therefore the diagnosis is delayed. In all previously reported cases eradicating surgery was performed.

We present the so far oldest case of congenital mastoidal cholesteatoma, a 87- year old woman. The process was found incidentally on radiology when admitted for dizziness.

The symptoms, radiological and intraoperative findings, and treatment is discussed in the light of previously reported cases.

Methods: We assessed the patient's medical history retrospectively. A conservative approach was applied with clinical follow-ups and radiology to evaluate any progress or new symptoms correlated to the cholesteatoma.

The Pub Med database was used to search for previously reported cases of congenital mastoidal cholesteatoma.

Results: There was no aural history and the tympanic membrane as well as audiometry were normal at admission. The initial high resolution CT and MRI with cholesteatoma protocol were conclusive. Large bone destructions were present. A one year follow-up with watchful waiting including aural examination and radiology will be presented. Previously, around 30 cases were reported, all being operated at ages ranging between 7 and 77.

Conclusions: This case shows the very slow progress of congenital mastoidal cholesteatoma as it had obviously prevailed during her 87 years of life. The case raises the question should congenital mastoidal cholesteatomas not be treated surgically but instead be handled conservatively, with watchful waiting, in the absence of disabling symptoms?