A lump or mass in the side or abdomen — when a kidney lump needs a scan

Almost always, no. Up to a third of small kidney masses turn out to be benign, and most kidney cancers that are found early are curable. A lump you can feel through the abdominal wall is far more likely to be something ordinary than a tumour. But because a small number are not, it is worth having examined rather than watched at home. Our kidney cancer hub covers the wider picture; this page stays with the lump itself.

Where the kidneys actually sit — your kidneys are not in the abdomen proper. They lie behind it, high against the back wall, tucked under the lower ribs, with the liver above the right one and the spleen above the left. Layers of fat, muscle and bowel sit between the kidney and your hand. That depth is why a kidney tumour is rarely felt at all, and why a lump you can find easily near the navel or the groin is usually coming from somewhere else entirely.

What most abdominal lumps turn out to be — hernias at the groin, the navel or an old surgical scar are the commonest by a wide margin. Next come lipomas, the soft mobile fatty lumps that form in the abdominal wall. A loaded bowel, a full bladder, the normal edge of the liver or spleen in a slim person, a knot in a muscle or the tip of a rib are all mistaken for masses every week in clinic. On the kidney itself, large simple cysts, angiomyolipomas and oncocytomas are benign and common enough that nobody should assume a kidney lump means cancer.

What a kidney mass feels like when it is felt — a palpable kidney mass is typically smooth and firm rather than craggy, sits in the flank between the lower ribs and the hip, and can be felt to move a little as you breathe in. It is usually on one side only. None of this is diagnostic. A doctor cannot tell what a lump is by feel alone, and neither can you. The examination decides how urgently a scan is arranged — it does not decide the answer.

• New or clearly growing. A lump that has appeared in recent weeks, or that is visibly bigger than it was, should be seen promptly rather than at your convenience.
• Hard or fixed rather than soft and mobile. A lump that does not slide under the skin and does not soften is the one doctors want to image.
• Arriving with other signs. Blood in the urine, unexplained weight loss, a persistent fever, night sweats or new swelling of one leg alongside a lump change the urgency.
• Pain is not the deciding feature. If a nagging ache between your ribs and hip is the main thing you have noticed, read persistent flank or side pain and kidney cancer.
• A firm abdominal lump in a child. This should be seen by a paediatrician within the same week, whatever else the child seems well enough to do.

Feeling well otherwise does not cancel any of these out. Kidney cancer is often silent until it is not, which is exactly why a new lump earns an appointment rather than a wait-and-see. Book a free consultation and have it examined.

One appointment and usually one scan is enough to answer the question. Here is the order it runs in at CION and what each step is actually for. Diagnosis — examination, ultrasound, contrast CT, MRI, biopsy and bloods — is delivered in-house by our own team. If your mass was found on imaging rather than by touch, a kidney mass found on a scan picks the story up from there.

1. 1

   History and examination

   Your oncologist asks how long the lump has been there, whether it has changed, and about blood in the urine, weight, fever, night sweats and family history. They then examine you lying flat, feeling for the mass from the front and the back at the same time — the way a kidney is examined rather than the way a stomach is. This takes the full 45 minutes we give every consultation.

2. 2

   Ultrasound of the abdomen

   Quick, painless and radiation-free, and it does the single most useful job: telling a simple fluid-filled cyst apart from a solid mass. A simple cyst usually needs nothing further at all. Anything solid, or a cyst with unusual internal features, moves straight to the next step.

3. 3

   Contrast CT of the abdomen

   This is the test that characterises a kidney mass. It shows the size, whether the mass takes up contrast — enhancement is the key feature that separates a tumour from a cyst — and whether nearby structures or the renal vein are involved. Where contrast CT is unsuitable, for example with reduced kidney function or a contrast allergy, an MRI is used instead.

4. 4

   Blood and urine tests

   A full blood count, kidney function, calcium and liver tests run alongside the imaging. They show how well the other kidney is working, and they pick up the changes in blood counts or calcium that some kidney tumours cause. A urine test checks for blood that is not visible to the eye.

5. 5

   Biopsy, only where it changes the plan

   A kidney mass is not always biopsied. Imaging alone is often enough to decide what happens next. A needle biopsy is used in selected situations — when the imaging picture is unclear, when a treatment other than surgery is being considered, or when a deposit from another cancer elsewhere is possible.

6. 6

   Tumour board, then a plan you understand

   Whatever the answer, it goes to a tumour board — medical, surgical and radiation oncologists reviewing it together, guided by NCCN recommendations for kidney cancer. If the mass is benign you are told plainly and given a follow-up interval. If it is cancer you get a written plan and a cost estimate before anything begins. Medical treatment runs in-house; kidney surgery and ablation are coordinated for you with specialist urology, uro-oncology and interventional radiology partners. The full route is set out on our kidney cancer treatment in Hyderabad page.

If the lump is only part of what you have noticed, these pages take the next question one level deeper.

• A kidney mass found on a scan — what happens next — the pathway when the mass was picked up by imaging rather than by touch, and what enhancement and Bosniak category mean on your report.
• Persistent flank or side pain and kidney cancer — when an ache between the ribs and the hip is worth investigating, and when it is muscular or from a stone.
• Kidney cancer — the complete guide — types, stages, risk factors and the full list of symptoms, in one place.
• Kidney cancer treatment in Hyderabad — how treatment is planned at CION, what is delivered in-house, and what is coordinated with specialist partners.

Not sure which of these applies to you? Book a free consultation and ask an oncologist directly.

Bring the lump to someone who will explain it

Every case at CION goes to a tumour board, not one doctor's opinion. If the mass turns out to be benign, we will tell you that plainly and send you home.

This page is general health information about a lump or mass felt in the side or abdomen. It is not a diagnosis and it cannot replace an examination. Only a doctor who has examined you and seen your imaging can say what a lump is. If you have a new or growing lump, visible blood in your urine, or unexplained weight loss, please arrange an appointment rather than waiting.