June 14, 2023
EDUCATIONAL PEARL
Glomus Tympanicum (Paraganglioma): Benign tumor of chemoreceptive cells
Notable Presenting Symptoms:
Pulsatile tinnitus (most common presentation),
Hearing loss
CN palsies
Red-purple middle ear mass (“setting sun” sign)
Brown’s sign (blanching TM with positive pressure)
Aquino’s sign (pulsation of paraganglioma decreases with carotid compression)
Epidemiology:
Most common benign tumor of temporal bone in adults
10% multiple; <5% malignant
1-3% associated with catecholamine secretion
20% family history associated with succinate dehydrogenase mutation
F>M
Pathophysiology:
Paraganglion cells that are neural crest in origin
Types of paragangliomas include:
Glomus Tympanicum: Grows near promontory along course of Jacobson’s nerve (tympanic branch of CN IX)
Glomus Jugulare: Grows near jugular foramen (the adventitia of bulb); primarily supplied by ascending pharyngeal artery
Glomus Caroticum: Grows in carotid body; most common H&N type
Glomus Vagale: Grows around vagus nerve at skull base
Glomus Tympanicum Classification (Glasscock-Jackson):
Type I: Small mass limited to promontory
Type II: Tumor completely filling middle ear
Type III: Within middle ear with mastoid extension
Type IV: Within middle ear and mastoid with extension into external auditory canal
Diagnosis:
Otoscopy/Neuro Exam
Temporal bone CT with contrast (glomus tympanicum without erosion of bone over jugular bulb)
MRI/MRA (“salt and pepper lesion” on T2)
Angiography
Audiogram
24-hr urine catecholamines if suspect secretory tumor
Treatment:
Surgical resection (transcanal versus extended facial recess approach) with consideration of pre-op embolization.
Radiosurgery used primarily for glomus jugulare.
Carlson ML, Sweeney AD, Pelosi S, Wanna GB, Glasscock ME 3rd, Haynes DS. Glomus tympanicum: a review of 115 cases over 4 decades. Otolaryngol Head Neck Surg. 2015 Jan;152(1):136-42.
Further Reading:
Written by: Graham Pingree
