A hard lump felt in the middle of the chest, on the breastbone itself, is in most people a normal part of the skeleton that has become easier to feel. The commonest single explanation is the joint a few centimetres below the collarbones where the two upper parts of the sternum meet at a slight angle, along with the second rib cartilage that attaches at exactly that level. A mild pectus shape accounts for many of the rest. It is often painless unless the joint itself is inflamed. Many people arrive having had an ultrasound arranged by their GP, which cannot answer a question about bone — a CT scan, and occasionally an MRI, is what settles it, and the majority are then discharged without any operation. Dr Lawrence Okiror, Consultant Thoracic and Robotic Surgeon (GMC 6150382), assesses chest wall lumps at London Bridge Hospital and The Lister Hospital Chelsea within 2–3 days. Self-referrals welcome.
Last reviewed: September 2026 · Dr Lawrence Okiror FRCS(CTh) FRCSEd(CTh) · GMC 6150382
The two upper parts of the breastbone meet at a slight angle. In some people that ridge is pronounced enough to be felt as a lump. It is present in everyone.
A lump with those three features is nearly always bone. Soft, mobile, or off to one side is a different question and belongs with the chest wall lump page.
Ultrasound does not see through bone and a plain X-ray shows the sternum poorly. A normal result from either does not exclude a bony cause. CT does.
The front of the chest is a small area with several quite different problems in it, and the location of what you can feel decides which page you need. This page is about the breastbone itself — the upper and middle part, from the notch at the base of the neck down to the level of the nipples.
On the bone, in the exact midline, upper or middle chest — this page.
At the very bottom tip of the breastbone — almost always the xiphoid process. Xiphoid process pain →
Off the midline, or soft and mobile under the skin — a different set of causes. Chest wall lump →
Pain with nothing to feel — the chest wall causes of unexplained pain. Unexplained chest pain →
Being able to feel a bone is not a disease. A hard, fixed lump in the exact centre of the chest, unchanged over months, is the normal anatomy of that region far more often than it is anything else.
The breastbone is not one bone. The upper portion, the manubrium, sits where the collarbones attach; below it lies the body of the sternum; and the two meet at a joint a few centimetres below the notch at the base of the neck. That joint does not lie flat — the two parts meet at a slight forward angle, which is why anatomists call it the sternal angle. Run a finger down from the notch at the base of your neck and the small step you come to is it.
In some people that angle is more pronounced than in others, and in a slim chest it is felt as a hard ridge or a distinct lump right in the midline. It is not a growth, it has not appeared, and it is present in everyone. What changes is your ability to feel it — which is why so many people become aware of it in adulthood having never noticed it before.
The same joint can, less commonly, become the source of symptoms in its own right. Degenerative change there produces a localised ache and tenderness at that exact point, worse on movements that flex the upper chest. It is uncommon, it is diagnosed on examination and imaging rather than guessed at, and it is not what most people with a prominence there have.
The second rib cartilage joins the breastbone precisely at the level of that joint, one on each side. That single piece of anatomy explains a great deal of what people describe. The prominence in the midline is the joint; any tenderness immediately beside it is the cartilage; and because they sit within a centimetre of one another, people quite reasonably report them as the same thing.
Separating them is the work of the examination, and it matters because they lead in different directions. A prominence on the bone with no tenderness needs an explanation and nothing more. Tenderness over the cartilage beside it, particularly with visible swelling, points towards inflammation of the cartilage — and where there is swelling as well as pain, the term used is Tietze syndrome rather than costochondritis. Both are covered on the unexplained chest pain page.
One practical point that comes up constantly: swelling from cartilage inflammation frequently outlasts the pain, sometimes by many months. People whose pain has settled but whose lump has not are often told the diagnosis cannot be right. It usually still is.
A distinct group of people come with no lump and no pain at all, but with a chest that does not look the way they expect it to. Most often it is the area where the collarbones meet the top of the breastbone — the sternoclavicular joints — standing out on either side of the notch at the base of the neck, and noticed far more in profile than face-on.
These joints are commonly asymmetrical, and one being more obvious than the other is normal. They are more visible in people who carry little fat over the upper chest, which is why the same person may see nothing for years and then notice it after losing weight, after a period of illness, or simply on catching sight of themselves at an angle. The bone has not moved. It has been uncovered. The same mechanism explains the lower breastbone becoming noticeable, which is covered on the xiphoid process page.
This is worth taking seriously rather than dismissing. People in this position describe avoiding certain necklines and feeling self-conscious in photographs, and they are frequently told there is nothing wrong without anyone explaining what they are looking at. There usually is nothing wrong — but the explanation is the point of the appointment, and it should be given properly.
These three words come up constantly in online discussions of chest shape, frequently used loosely, and they are worth defining plainly because the distinction changes what, if anything, is recommended.
The overwhelming majority of people with any of these shapes do not need an operation. That is worth saying clearly, because online discussion tends to reach for surgery quickly. A chest wall shape that has been present since adolescence, has not changed, and causes no breathlessness or exercise limitation is a variation rather than a disease.
Where correction is genuinely in question, it is decided on symptoms and on the effect on the structures behind the sternum, not on appearance alone. Pectus surgery in England is not routinely commissioned and is concentrated in a small number of centres with a national multidisciplinary team, so anyone pursuing it should expect to be assessed by a pectus service. The position is set out further on the Nuss bar removal page, which also covers what happens to people who had a repair and now need the bar taken out.
A great many people arrive having had an ultrasound arranged by their GP, and having been told it showed nothing. That is a reasonable first test for a lump under the skin, and a poor one for a lump on a bone. Ultrasound does not see through bone. It reports the soft tissue in front of the sternum, which is not where the problem is.
A plain chest X-ray is scarcely better for this particular question. The sternum sits directly in front of the spine and the heart, and on a standard front-facing film all three are superimposed, so sternal abnormalities are frequently invisible. A normal chest X-ray is therefore not reassurance about a bony lump on the breastbone. It simply has not looked.
CT is the test that answers it. It shows the sternum, the joint, the rib cartilages and the bone within, and it separates normal anatomy from anything else with little ambiguity. MRI is added where the marrow inside the bone or the soft tissue around it needs assessing, or where something has already been seen and needs characterising. Which of these applies is a decision to make at the consultation — not everyone needs a scan at all, and an unnecessary CT carries a radiation dose for no benefit. More on what each test shows is on the chest imaging page.
Bring whatever you have already had. Knowing precisely what has been excluded is more useful than repeating it, and it frequently shortens the pathway rather than lengthening it.
A small proportion turn out to be something other than the shape of the skeleton. They generally declare themselves by how they behave rather than by how they look, which is the reason the history matters as much as the examination.
Not becoming easier to feel as you lose weight, but measurably larger over weeks to months. That is the single most important feature in the history and the one worth being honest with yourself about.
Night pain in a bone, particularly if it responds strikingly well to anti-inflammatory tablets, is a pattern associated with certain small benign bone lesions. It is uncommon, it is treatable, and it is easily missed for years if nobody asks the question.
Then it is probably not sternum at all. A lipoma or a sebaceous cyst is far more likely, and those have their own assessment. Chest wall lump →
Particularly at the joint where the collarbone meets the breastbone. Infection in that joint is uncommon but it needs prompt assessment rather than an outpatient appointment in a few weeks.
A new bony lump on the sternum in someone previously treated for cancer, particularly breast cancer, is assessed differently and more urgently. Breast cancer spread to the chest →
None of these features means the answer will be bad. They mean the question deserves a proper answer rather than reassurance offered without examination.
An examination, a review of any imaging you have already had, and where necessary the right scan — which for a bony lump usually means CT rather than a repeat ultrasound. Most people are then told what they are feeling, why they became aware of it, and that nothing needs to be done. Being discharged after one appointment is the commonest outcome and it is a good one.
It is worth saying which specialty owns this, because it is a frequent source of delay. The sternum, the rib cartilages and the chest wall are thoracic anatomy. People with a lump here are often sent between general practice, breast services, orthopaedics and rheumatology without anyone naming the specialty responsible for the front of the chest. A thoracic surgical opinion is the appropriate next step once anything urgent has been excluded.
Dr Okiror assesses chest wall lumps at London Bridge Hospital and The Lister Hospital Chelsea, with outpatient consultations also available at the HCA clinics in Canary Wharf and the City of London, and sees patients from the age of 16 upwards. Private appointments are typically available within 2–3 working days. Self-referrals welcome. Second opinions are available for patients already under another team’s care.
Questions most commonly asked by people who have found a hard lump in the middle of the chest, or whose breastbone has started to look more prominent.
Book an Assessment →Or call Jo Mitchelson:
020 7952 2882
Self-referrals welcome. Private appointments at London Bridge Hospital and The Lister Hospital Chelsea within 2–3 days. Dr Okiror examines the chest wall personally, arranges the right scan where one is needed, and tells you plainly what you are feeling.
Jo Mitchelson, PA · 020 7952 2882 · pa@lungsurgeon.co.uk
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