Glomus jugulare tumour

Epidemiology & clinical

• Adult, F > M.
• Can be sporadic or familial (may be multicentric with carotid body / vagal / adrenal phaeo).
• Usually non–catecholamine secreting (but always a small “functional” risk).

Symptoms

• Otologic
  • Pulsatile tinnitus.
  • Conductive hearing loss, aural fullness.
  • Sometimes vertigo.
• Cranial nerve
  • Lower CN palsies (IX, X, XI ± XII) → dysphagia, hoarseness, shoulder weakness.
• ENT exam
  • Red retrotympanic mass (“rising sun”) if extension to middle ear (jugulotympanic).
  • Brown’s sign: mass blanches with positive pressure (pneumatic otoscopy).

Imaging

CT (bone and soft tissue)

• Bone window
  • Irregular widening / “moth-eaten” destruction of jugular foramen.
  • May destroy caroticojugular spine.
  • Extension into:
    • Hypotympanum → middle ear (jugulotympanic).
    • Mastoid air cells.
    • Petrous apex ± posterior fossa.
• Soft tissue
  • Homogeneous to mildly heterogeneous soft-tissue mass.
  • Strong, early enhancement after contrast.
  • May cause smooth remodelling + aggressive permeative change.

MRI

• T1: iso–hypointense to muscle.
• T2: typically hyperintense, but with mixed signal.
• “Salt-and-pepper” pattern in larger lesions:
  • Pepper = multiple flow voids (high-flow vessels).
  • Salt = foci of slow flow / haemorrhage.
• Post-contrast: avid, often heterogeneous enhancement.
• Evaluate:
  • Middle-ear cavity, mastoid, petrous apex.
  • Intracranial extension (dural contact, posterior fossa mass effect).
  • Internal auditory canal, clivus, cavernous sinus (for large ones).

Angiography (DSA)

• Intense tumour blush with early venous drainage.
• Helps:
  • Confirm diagnosis.
  • Map feeders for pre-op embolisation.

Vascular supply

• Main feeders (ECA)
  • Ascending pharyngeal artery (key).
  • Occipital artery.
  • Posterior auricular artery.
  • ± Superficial temporal / internal maxillary branches.
• Secondary
  • Caroticotympanic branches of petrous ICA.
  • Meningohypophyseal trunk (if intracranial).
  • Small vertebral branches.

Classification

• Fisch classification (A → D) roughly:
  • A/B: confined to middle ear / hypotympanum.
  • C: infralabyrinthine / apical involvement, major skull-base disease.
  • D: intracranial extension.
• Exam use: higher Fisch = nastier skull-base tumour, harder surgery.

Differential diagnosis

• Glomus tympanicum
  • Confined to middle ear, jugular foramen intact.
  • Small retrotympanic mass hugging cochlear promontory.
• Glomus jugulotympanic
  • Glomus jugulare that has extended into middle ear.
  • So: both middle-ear mass + eroded jugular foramen.
• Glomus vagale
  • High neck carotid-space mass (C1–C3).
  • Splits ICA (anteromedial) and IJV (posterolateral).
  • Neck lump + hoarseness; no primary jugular foramen erosion.
• Jugular foramen schwannoma (IX–XI)
  • Less vascular, no salt-and-pepper, more solid.
  • Often smooth bony expansion rather than moth-eaten destruction.
• Meningioma
  • Dural-based, may have hyperostosis rather than permeative erosion.
  • Less flow voids, usually more homogeneous enhancement.
• Metastasis / other malignancy
  • Clinical context of known primary.
  • Less classic vascular pattern.

Exam nuggets

• Often multiple paragangliomas → check carotid body / vagal / contralateral jugular + adrenal (for phaeo).
• Think of underlying SDH gene mutations in young / multifocal cases.