Brain Pathology Case of the Month - July 2001

Contributed by Dean M Havlik, MD1, Blaine L Hart, MD2 and Mark W Becher, MD1
  University of New Mexico School of Medicine, 1Department of Pathology and 2Department of Radiology, Albuquerque, New Mexico
Published on line in June 2001


The patient is a 58 year-old man who had a rubella virus infection with acute otitis media as a child and decreased hearing in his right ear since childhood. He presented to the hospital with a two-year history of dizziness and vertigo.


CT scan and MRI of the head were performed. CT scan (Fig. 1) showed a soft tissue density mass and extensive destruction of the right petrous temporal bone. Fragments of bone remain along the medial aspect of the mass (arrows). MRI (Figs. 2, 3) demonstrated a large heterogeneous mass, approximately 6.5 x 4.0 x 4.0 cm, originating from the petrous portion of the right temporal bone that did not have significant enhancement after contrast administration. It showed mild increased signal on T1-weighted images (Fig. 2) with heterogeneous signal on T2-weighted images (Fig. 3). The mass extended into the posterior fossa and displaced the cerebellum medially without evidence of invasion, suggesting a slow growing process. It appeared to be confined to the extradural space without brain involvement and the discontinuous thin layer of bone between the mass and dura seen on CT scan was confirmed. The mass extended into and filled the right external auditory canal and surrounded the medial aspect of the right internal auditory canal but the contents of the internal auditory canal appeared intact and free of invasion. The patient underwent surgical resection of the mass.



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