Neoplasms

Question 1

Hemangiomas

Answer 1

• Benign, vascular tumor
• Common to the temporal bone
• Presents around the 1st month of life
• Typically results from abnormal angioblastic fetal tissue
• Characterized by initial rapid growth followed by a slow period of involution
• Diagnosed with imaging (high resolution CT or MRI with contrast because T2 will illuminate vascularity)
• Signs and symptoms depend on site of lesion but may include:
  
  • hemifacial spasm
  • tinnitus
  • CHL or progressive SNHL
  • Vertigo
    Differential Dx: Meningioma, facial nerve schwannoma, and cholesteatoma
    Tx: Surgical removal with low likelihood of recurrence

Question 2

Vascular Malformation

Answer 2

• Benign, vascular tumor
• Common to the temporal bone, typically arising from the IAC (facial nerve “7 up”), rarely in the ME or EAC.
• differs from a hemangioma histologically, but they still get confused
• Diagnosed with imaging (high resolution CT or MRI with contrast because T2 will illuminate vascularity)
• Signs and symptoms depend on site of lesion but may include:
  
  • hemifacial spasm
  • tinnitus
  • CHL or progressive SNHL
  • Vertigo
    Differential Dx: Meningioma, facial nerve schwannoma, and cholesteatoma
    Tx: Surgical removal with low likelihood of recurrence

Question 3

Schwannoma

Answer 3

• Benign, extra-axial tumors
• Most common benign tumor of the temporal bone and CPA
  
  • 3 sites in the temporal bone: IAC CN
    VIII, jugular foramen on CN IX and X,
    and fallopian canal on CN VII.
• arises from schwann cells (connective tissue that forms the myelin sheath for the peripheral nervous system)

Question 4

Vestibular Schwannoma

Answer 4

• schwannoma on CN VIII, commonly originating in the IAC and grows into the CPA
• slow growing, typically diagnosed ~40-60 yrs
• typically unilateral, except for NF2 patients
• S/S depend on location:
  
  • otologic phase: compression of
    structures in and around IAC
  • neurologic phase: tumor
    compresses other intracranial
    structures
  • signs and symptoms are almost
    always IPSILATERAL to the lesion
• and size:
  
  • small (1-4 cm): HL, headache, tinnitus, unsteady gait, imbalance/dizziness
  • moderate: facial sensory disturbances, facial twitching, nystagmus
  • Large: Can compress the fourth ventricle leading to an increase intracranial pressure, hydrocephalus, coma, death
    Differential Dx:
• Meningioma
• NF2
• Facial Nerve Schwannoma
• Epidermoid/Dermoid cysts
• Endolymphatic Sac Tumors

Question 5

Meningioma

Answer 5

Benign brain tumor (one of the most common of the CNS) but can be invasive locally, disturbing vascularity, cranial nerves, and calcifying
Arise from the meninges so typically superficial, occasionally showing up in the IAC and CPA
More common in females (2:1) because of their association with progesterone levels and breast cancer
Etiology:
- associated with NF2
- Radiation therapy to the head
- Genetics (abnormalities of chromosomes 1,7, 10, 14, and DiGeorge syndrome)
Tumor size depends on location
S/S depend on location and are rarely present. Most likely present if it is closer to the IAC. S/S include:
- progressive unilateral SNHL
- Vertigo
- Tinnitus
- Nausea
- Abnormal ARTs with retrocochlear pattern
- Abnormal ABR
- Normal OAEs if hearing is normal
Differential Dx:
- Otitis media
- Paraganglioma
- CN VII neuroma
- Vestibular schwannoma

Question 6

Cortical Tumors

Answer 6

Tumors in the cortex
Auditory signs when tumor is near or on the auditory cortex
Peripheral testing will be normal. WRS may be abnormal and inconsistent with audiogram
S/S include:
- headaches
- dizziness/unsteadiness
Signs will be contralateral to site-of-lesion

Question 7

Benign Tumors of the Temporal Bone

Answer 7

• Osteoma
• Paraganglioma
• NF2
• Facial Nerve Schwannoma

Question 8

Malignant Tumors of the Temporal Bone

Answer 8

• squamous cell carcinoma
• adenocarcinoma
• rhabdomyosarcoma

S/S include:
- HL and vestibular symptoms
- Otalgia
- Otorrhea
- Tinnitus
- Facial paralysis
- Headache

Differential Dx:
- chronic otitis media

Question 9

Metastatic Tumors that Can Affect the Temporal Bone

Answer 9

• Breast cancer
• Lung cancer
• Renal carcinoma, GI, and liver adenocarcinoma
• Lymphoma and leukemia
• Thyroid cancer
• Osteoblastoma
• Melanoma