Glomus Tumours and Pulsatile Tinnitus: The Rare Cause, Described Accurately

This is the diagnosis people are afraid of when they search their pulsatile tinnitus at two in the morning, so it deserves a page that neither buries it nor inflates it.

A glomus tumour is real, it is uncommon, it is almost always benign, and the two symptoms it most often produces are precisely hearing loss and pulsatile tinnitus. That last fact is why it earns a mention in every workup — and why it is worth being able to read a description of it that does not read like a diagnosis of yourself.

What it is

A 2023 review in Current Treatment Options in Oncology describes temporal bone paragangliomas as indolent, classically benign and highly vascular neoplasms of the bone that houses the ear. Take those three words individually, because each carries information:

• Indolent — slow. These are not fast-moving tumours, and time is usually available for decisions.
• Classically benign — non-malignant in the overwhelming majority of cases. The hedge in "classically" is deliberate and honest, not evasive.
• Highly vascular — full of blood vessels. This is both why they make a rhythmic sound and why operating on them is difficult.

The review divides them by location into tympanomastoid paragangliomas, sitting behind and around the eardrum, and tympanojugular paragangliomas, centred on the jugular foramen at the base of the skull where the great vein leaves and several nerves pass. The older names — glomus tympanicum and glomus jugulare — describe the same division, and are still what most people find when they search.

Why it sounds like a heartbeat

A tumour packed with blood vessels, sitting directly against the middle ear, is an acoustic source in a way that most growths are not. Blood pulsing through it is happening on the other side of the eardrum, which is a far better transmission path than anything reaching the ear through the skull.

That mechanism puts it in the same category as sigmoid sinus wall abnormalities: a real physical sound made near the ear, not a phantom signal generated by the auditory system. It is also part of why some of these cases are objective — a clinician can sometimes hear it too.

What the numbers look like

The best-quantified picture comes from a 2022 systematic review and meta-analysis in World Neurosurgery covering 23 studies and 460 patients with glomus jugulare tumours treated with stereotactic radiosurgery. Its figures for presenting symptoms:

• Tinnitus — 56% (95% CI 46–66)
• Hearing loss — 56% (95% CI 44–68)
• Lower cranial nerve deficit — 42% (95% CI 31–54)

That third one is the reason these tumours matter clinically. The nerves passing through the jugular foramen control swallowing, the voice and tongue movement, and a tumour growing there presses on them. Hoarseness, difficulty swallowing or a weak shoulder alongside pulsatile tinnitus is a materially different presentation from pulsatile tinnitus alone.

Note also what these percentages are and are not. They describe people who reached a centre and were treated for a jugular tumour, not people with pulsatile tinnitus in general. Read as "of those who had this, 56% had tinnitus" — never as anything about the likelihood of having it.

Treatment: the interesting part is that watching counts

The traditional answer was surgery. The 2023 review is direct about why that is no longer the automatic answer: surgery is challenging due to the close proximity of tumour to critical neurovascular structures, with a high risk of complications, especially in advanced lesions. A benign, slow-growing tumour wrapped around cranial nerves is a case where the operation can cost more than the tumour does.

So the review reports that radiotherapy and active surveillance have been increasingly recommended for selected patients, and that the decision should be made comprehensively rather than by default.

The radiosurgery evidence, from the same meta-analysis:

• Tumour control at follow-up: 95% (95% CI 93–97), mean follow-up 47 months.
• Overall clinical improvement: 47% (95% CI 37–57).
• Tinnitus improved in 54% (95% CI 44–63).
• Hearing loss improved in 28%, lower cranial nerve function in 22%.

Tumour control is not the same as cure. It means the tumour stopped growing, which for an indolent benign lesion is usually the goal — but a 95% control rate sitting beside a 47% symptom-improvement rate is the honest shape of this treatment, and the two numbers get conflated constantly. Roughly half of people had their symptoms improve. The tinnitus figure, 54%, is the best of the three symptom outcomes.

One limitation the paper states about itself: the literature search was run in March 2019, three years before publication. And the authors close by asking for further studies to evaluate the role of radiosurgery, which is not the language of a settled question.

The tests that are not about your ear

Two parts of the workup surprise people, and both have good reasons.

Catecholamine testing. Paragangliomas belong to a family of tumours that can secrete adrenaline-type hormones, and the review lists biochemical testing of catecholamines in the routine workup alongside the conventional physical and laboratory examinations. That is a test of your blood chemistry, not of your ear, and it is checking what kind of tumour this is rather than how loud the sound is.

Genetic testing for SDHx mutations. The review lists this too, in the same sentence. SDHx testing looks for inherited mutations, which is what makes this the one part of a tinnitus workup that can turn out to be about your relatives as well as about you. The review does not put a number on how often the mutations are found, so this page will not either — but knowing in advance that the question may come up is better than meeting it cold in a consulting room.

The review's final point is about time: long-term follow-up with clinical, laboratory and radiological examination is described as essential for all patients, whatever the treatment. That is normal for an indolent tumour, and it is not a signal that something is going badly.

Reading this without frightening yourself

The reason this article exists is that pulsatile tinnitus gets a workup and glomus tumour is on the list that workup checks. The reason to keep proportion: it is one entry on a list that mostly turns up blood pressure, anemia, a vein or bone variant, or raised intracranial pressure.

What separates useful vigilance from anxiety here is specificity. The things that genuinely raise the question of a mass are checkable and mostly not by you: a red mass visible behind the eardrum on examination, hearing loss on the same side, and new problems with swallowing, voice or tongue movement. An ENT examination and, when indicated, imaging answer this. Reading about it does not, and cannot.

What to do with this

• If you have one-sided pulsatile tinnitus, get it examined and, if advised, imaged. That is the whole action item, and it is the same one whether or not this article is relevant to you.
• If your pulsatile tinnitus comes with new hoarseness, swallowing difficulty or tongue weakness, say so explicitly. That combination points at the jugular foramen and changes the urgency.
• If a glomus tumour has been found, the words that describe it are indolent and classically benign, surveillance is a legitimate option for selected patients, and the decision is not automatically an operation.
• If radiosurgery has been proposed, the numbers to have in mind are 95% tumour control and roughly a coin-flip chance of symptom improvement, with tinnitus the most likely of the symptoms to improve.
• If genetic testing is offered, it is standard for this tumour type, and the results can matter to your relatives as well as to you.

A glomus tumour is on the short list of tinnitus causes that can genuinely be treated at the source rather than managed — with the qualification this page has already made, that 95% tumour control and 54% tinnitus improvement are two different numbers and only the second is about how you feel.