Medical Specialties

At the Center for Neurosciences, we work together across specialties to provide the best, most comprehensive approach to treatment.

Epidermoids of the Petrous Apex

Epidermoids are slow-growing, benign (non-cancerous) cysts that are typically congenital (present at birth). They result from skin cells that are misplaced during embryogenesis and left behind while the nervous system is developing. Epidermoids can be found in the petrous apex, a pyramid shaped portion of the temporal bone located 3-4 centimeters deep to the middle ear. While epidermoids are present at birth, symptoms are generally not experienced until adulthood because the cyst is too small at first to produce any symptoms. As the epidermoid grows, it may erode the petrous apex bone and invade the inner ear, facial nerve, petrous carotid artery, vestibulocochlear nerve, trigeminal nerve and the brain itself. Hearing loss, dizziness, facial weakness, retro-orbital headaches and sensory abnormalities of the face are early symptoms. Meningitis may occur if the epidermoid ruptures.

Diagnostic workup for petrous apex lesion includes a comprehensive audiogram (hearing test) and high resolution imaging studies, including both CT and MRI scans. Surgery is the only treatment for symptomatic epidermoids, but it is often not possible to remove all of the epidermoid tissue during surgery. Therefore, continued monitoring with serial CT/MRI scans as well as repeat surgery for recurrent symptoms may be recommended.

Why Choose Us

  • Dr. Abraham Jacob, Medical Director for Ear & Hearing (E&H) at the Center for Neurosciences (CNS), is fellowship trained in Otology, Neurotology, and Cranial Base Surgery. He is the first and most experienced Neurotologist recruited to Southern Arizona.
  • Dr. Jacob was a founding member of the University of Arizona (UA) Department of Otolaryngology prior to his departure and transition to CNS. At UA, he was Vice Chair of ENT and held the rank of full Professor with Tenure.
  • Dr. Jacob transitioned his practice to the Center for Neurosciences in early 2017 as he felt that the new environment helped to optimize delivery of personalized ear and lateral skull base care.
  • Dr. Abraham Jacob is uniquely qualified to offer a variety of skull base approaches to petrous apex epidermoids including transotic, translabyrinthine, transcochlear, transpetrosal and middle fossa craniotomies.
  • The extensive resources of Center for Neurosciences as well as the Tucson Medical Center bring neurosurgeons, neuroradiologists, tertiary care operating rooms and a neuro/critical care intensive care to optimize clinical outcomes from surgery.