Imaging findings in auto-atticotomy.
OBJECTIVE
An acquired attic cholesteatoma may spontaneously drain externally into the external auditory canal, leaving a cavity in the attic with the shape of the original cholesteatoma but now filled with air, a phenomenon referred to as "nature's atticotomy" or auto-atticotomy. We describe and quantify the CT appearance of the auto-atticotomy cavity as it pertains to the appearance of the scutum and the lateral attic wall.


METHODS
Twenty-one patients with erosion of the scutum and loss of the lower attic wall on MDCT were identified during a 5-year span. Images were assessed for measureable widening of the space between the ossicles and the lower lateral attic wall in the axial and coronal planes. Three measurements of the lateral attic were made on the axial images. Findings were compared with the same measurements in 20 control subjects.


RESULTS
The 21 patients had a characteristic blunting of the scutum with loss of the lower lateral attic wall and widening of the lateral attic, consistent with an auto-atticotomy. There was a statistically significant (P < .001) widening of the lateral attic dimensions in the axial plane in the patients with auto-atticotomy.


CONCLUSIONS
Spontaneously evacuated cholesteatoma may mimic a surgical atticotomy on MDCT. Scutal erosion and attic enlargement with a smoothly contoured bony remodeling of the lower lateral attic wall in a patient with no history of surgery suggest that a cholesteatoma was previously present and spontaneously drained.
Department of Radiology, Abington Memorial Hospital, Abington, Pennsylvania.
M
M
Manasawala
M E
ME
Cunnane
H D
HD
Curtin
G
G
Moonis
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018424:Cholesteatoma, Middle Ear / Q000000981:diagnostic imaging*; D003937:Diagnosis, Differential; D004432:Ear, Middle / Q000000981:diagnostic imaging* / Q000601:surgery*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography / Q000379:methods*; D010034:Otitis Media with Effusion / Q000000981:diagnostic imaging*; D013506:Otologic Surgical Procedures / Q000379:methods*