Head and Neck Notes

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TEMPORAL

Glomus means paragangliomas

GLOMUS TYMPANICUM

- Extra adrenal pheochromocytoma isolated to the
middle ear
- Vascular RED mass behind the tympanic
membrane
Differentials
o Glomus tympanicum
o Abberant carotid artery
o Tympanic membrane hemangioma



FACIAL NERVE SCHWANNOMA

CHOLESTROL GRANULOMA

- Aka cholesterol cyst
- BLUE mass behind tympanic membrane, but occurs most commonly in the petrous apex
- Soft tissue middle ear mass behind the tympanic membrane
- Giant cell reaction to cholesterol crystal incited by obstructed air cell
- Also presents with bony erosion



CHOLEASTEATOMA

- Differential of cholesterol cyst
- Will restricted diffusion on MR, Cholesterol granuloma will appear as white
- May represent a sequela of chronic tympanic membrane perforation
- If present, always take note of involvement of lateral semicircular canal, facial nerve and tegmen
tympani
- If acquired, occurs usually in the middle ear. if congenital, usually anywhere including the
petrous apex



LABYRINTHITIS

- Inflammation of inner ear
- Enhancement of affected inner ear structures on MRI
Stages
Acute labyrinthitis
▪ Pus in the inner ear. Enhancement may only be the sign on MRI
Fibrous labyrinthitis
▪ Endolymph and perilymph replaced by bony strands

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Labyrinthitis ossificans
▪ Calcified debris line the endolymph and perilymph

PARAGANGLIOMA

- Tumors that arise from sympathetic glomus bodies
- Identical to extra adrenal pheochromocytoma



GLOMUS JUGULARE

- MOST COMMON PRIMARY TUMOR OF THE JUGULAR FORAMEN

GLOMUS TYMPANICUM

GLOMUS JUGUOTYMPANICUM

GLOMUS CAROTICUM

- CAROTID BODY TUMOR

GLOMUS VAGALE

- VAGUS NERVE