Cholesteatoma
Findings:
An erosive soft tissue mass is present in the left middle
ear involving Prussak's space, with erosion of the scutum and ossicles.
Differential Diagnosis:
90% of cases with this constellation of findings will
be cholesteatoma. Cholesterol granuloma, metastasis, rhabdomyosarcoma,
and carcinomas such as squamous cell, adeno, and adenoid cystic could also
be considered. This is the wrong location for glomus tympanicum (cochlear
promontory), and the findings are not consistent with vascular lesions.
Discussion:
-acquired cholesteatoma
-98% of middle ear cholesteatomas, pars flaccida
-Prussak's space with medial ossicular displacement,
+/- bone destruction
-complications:
-conductive
hearing loss due to ossicular destruction
-labyrinthine
fistula, facial n., tegmen erosion
-intracranial
extension, sigmoid sinus erosion/thrombosis, automastoidectomy
-intracranial
abscess, meningitis
-CSF rhinorrhea
reference: Harnsberger, H. Handbook of Head and Neck Imaging 2nd Ed. 1995: Mosby Year Book. pp. 444-447.