Patients with facial palsy and middle ear disease, which may be chronic but clinically occult, may have a cholesteatoma with extension medially along the facial canal. In two patients, axial computed tomographic (CT) scans demonstrated involvement of the medial petrous bone. Patients with vertigo and chronic middle ear disease may have a cholesteatoma with a "fistula" between the middle and inner ears. Although the fistula usually involves the lateral semicircular canal, the cholesteatoma may pass through the oval window. In two patients, coronal CT scans showed extension to the oval window in one and through it in the other.