WhatsApp Skip to main content

Dr. Harsh J Shah

Four Kinds of Small Bowel Tumour: Which One Is Yours?

Last updated: 05-Nov-2026

Dr Harsh Shah, GI surgeon, Ahmedabad

Dr Harsh Shah
MS, MCh (Surgical Gastroenterology), DrNB (Surgical Gastroenterology)
Registered with Gujarat Medical Council, Reg. No. G-38738
Intestine Cancer Surgeon
Dr. Jivraj Mehta Hospital, Vasna, Ahmedabad · 18 years of experience

In short

The word “small bowel cancer” covers four different tumours. They are a gland-forming cancer, a neuroendocrine tumour, a lymphoma and a GIST. Each starts in a different cell and needs a different plan.

The tissue report names the kind, and the kind decides the operation. A lymphoma is treated mainly with medicine. A GIST is removed without clearing the lymph nodes. A gland-forming cancer needs the nodes removed.

Two tests carry most weight in a gland-forming cancer. They are MMR, which can open the way to immunotherapy, and HER2, which can point to a targeted drug.

To see how these tumours are treated here, read our small bowel cancer treatment page. This post explains what the tissue report means.

Why does the type of tumour matter before anything else?

The type decides the operation, the lymph node plan and whether medicine comes first. A wrong guess at the start can lead to too big an operation, or too small a one.

  • Assuming a gland-forming cancer when it is a lymphoma can mean a large operation for a disease that medicine treats.
  • Assuming it for a neuroendocrine tumour can mean the lymph nodes in the bowel’s fold are left behind.
  • Assuming it for a GIST can mean nodes are removed that did not need to be.

This is why a good tissue sample, read by a pathologist who sees these tumours often, comes before the plan.

What are the four kinds of small bowel tumour?

Each kind starts in a different cell. Where it sits in the bowel, how it is staged and how it is treated all follow from that cell.

The four kinds of small bowel tumour at a glance
KindStarts inWhere it often sitsMain treatment
Gland-forming cancer (adenocarcinoma)The glandular liningThe duodenum, near the bile duct openingSurgery, then chemotherapy when nodes are involved
Neuroendocrine tumourHormone-making cellsThe last part of the small bowelSurgery with clearing of the bowel’s fold, then injections or targeted treatment if needed
LymphomaLymph cellsOften the ileumMedicine, with surgery only for complications
GISTPacemaker cells of the gut wallThe jejunum or ileumSurgery without node removal, and a targeted tablet when the risk is high

How common each kind is depends on the series. Hospital series count more gland-forming cancers, because they present with a block and are operated on. For who is at risk and how rare the disease is, see our post on how rare it is.

What does the report say about a gland-forming cancer?

Most are moderately formed gland cancers that look like bowel cancer under the microscope. The report lists the type, the depth, the margins and the lymph nodes.

Lines in a gland-forming cancer report and what each tells you
Line in the reportWhat it tells you
Type of cancerSignet-ring and poorly cohesive types behave harder; medullary type often does better
Depth of growthHow far through the wall it went, which sets the stage
MarginsWhether cancer reaches the cut edge, which decides if more treatment is needed
Lymph nodes examined and involvedHow reliable the stage is, and whether chemotherapy is advised
Vein or nerve invasionA sign of a higher chance of return
MMR resultWhether immunotherapy and a family check are needed

One line deserves attention. Survival tracks with how many nodes the pathologist found. Too few suggests the nodes were not fully cleared in the operation, so ask about it.

Which tests on the tissue change the drugs?

Three tests do. They are the MMR check on every gland-forming cancer and HER2 when the cancer has spread. A wider gene panel is added for spread disease.

  1. MMR is checked first, on every case. It is cheap and quick.
  2. If the MMR proteins are missing, more tests separate a chance change in the tumour from an inherited one.
  3. In spread disease, HER2 is added. So is a gene panel that looks for changes in genes such as KRAS and BRAF.
  4. Where tissue is scant, a blood test for tumour DNA may help, though it is not routine here yet.

These tests are about drug choice and family safety. They do not change the fact that the tumour needs to be removed when it can be.

Why do doctors ask about MMR so often?

A good share of gland-forming small bowel cancers cannot repair copying errors in their DNA. Such a tumour can respond strongly to immunotherapy, which is why this single result matters so much.

  • MMR-deficient tumours sit more often in the duodenum, in people with coeliac disease, and in the medullary type.
  • Immunotherapy is the main lever in spread disease when this change is present.
  • The same result can point to Lynch syndrome, an inherited condition, so relatives may need advice.
  • Stage for stage, these tumours often do better, and they gain less from some older chemotherapy drugs.

For how these results shape drug choice, read what the guidelines advise, and for the studies behind it, the key trials.

How is a neuroendocrine tumour graded?

Grade says how fast the cells divide, and it is the main driver of the plan. It rests on a stain called Ki-67, a count of dividing cells, and how well formed the cells look.

Grades of a neuroendocrine tumour in plain terms
GradeHow the cells divideWhat it means
G1SlowlyUsually quiet over many years
G2At a middle paceNeeds closer follow-up
G3, well formedFast, but cells look orderlyMay still respond to hormone-based and radiolabelled treatment
Poorly formed carcinomaFast, and cells look disorderlyTreated like small-cell cancer, mainly with chemotherapy

A G3 tumour with orderly cells and a poorly formed carcinoma can show the same Ki-67 number. They are different diseases. This is why the pathologist’s look at the cells matters as much as the number.

What else does a neuroendocrine tumour report tell you?

The report should show more than the grade. It should say how many tumours were found, how big and how deep. It should also say whether the nodes and the bowel’s fold are involved.

  • These tumours often come in several places, so the whole small bowel is checked during the operation.
  • They often cause scarring in the bowel’s fold, and that scarring causes most of the trouble, not the small primary.
  • A marker called SSTR tells whether somatostatin-based drugs and radiolabelled treatment can work.
  • Flushing and loose motions usually appear only after spread to the liver.

If a patient has flushing, the anaesthetist must know before any operation. Handling these tumours can set off a sudden surge of hormones, so medicine is given to prevent it.

What do lymphoma and GIST reports show?

Both are named by a small set of stains. The report then adds the details that set treatment: the lymphoma subtype, or the GIST size, cell-division count and gene change.

Stains that separate the four kinds on a biopsy
StainGland-forming cancerNeuroendocrineLymphomaGIST
Cytokeratin (gland marker)PositiveOften positiveNegativeNegative
Synaptophysin, chromograninNegativePositiveNegativeNegative
CD45, CD20, CD3NegativeNegativePositiveNegative
KIT, DOG1NegativeNegativeNegativePositive
  • For lymphoma the subtype matters. A tumour that grows on a coeliac background can tear the bowel as it shrinks. The team therefore watches closely during chemotherapy.
  • For GIST the size, the cell-division count and the site set the risk of return. A small bowel GIST is more active than a gastric one of the same size.
  • The GIST gene change guides the tablet and its dose. Most respond to imatinib, but one change in the PDGFRA gene does not, and needs another drug.

For how a GIST is treated, see our GIST treatment page.

Does the report change the operation?

Yes. Once the type is known, the operation, the margins and the lymph node plan follow. Each kind has its own rule.

How the type of tumour shapes the operation
KindThe operationLymph nodes
Gland-forming cancerRemoval of the bowel segment with its fold; near the bile duct opening, a larger operationCleared widely, and counted
Neuroendocrine tumourRemoval of the tumour and the scarred fold, even for a small tumourCleared with the fold
LymphomaMainly none; surgery for a block, a tear or bleedingNot the aim
GISTRemoval of the tumour with a clear edge and no ruptureNot routinely removed

Each of these plans also depends on the stage and on your fitness. The tumour board weighs the report with the scans. For the order of tests that leads here, see our post on tests and their order.

What is different for patients in India?

Two things. The mix of tumours may include more neuroendocrine tumours and lymphomas than Western reports show. And gut tuberculosis can pass for a tumour at every step.

  • Fresh tissue should be sent for tuberculosis tests whenever a stricture or mass is unclear.
  • MMR testing is available widely. HER2 and gene panels sit mostly at larger cancer centres and private labs.
  • Where tests are not available on site, the tissue block should be kept and sent out, not skipped.
  • Radiolabelled treatment for neuroendocrine tumours and immunotherapy are available at selected centres.

Your tissue block belongs to you. Ask for it, and bring it to the consultation.

What should you ask about your report?

Ask each of these without worry. A good team will answer plainly.

  • Which of the four kinds is this tumour, and which stains proved it?
  • Was a pathologist who sees these tumours often involved?
  • Was the MMR test done, and what did it show?
  • For a neuroendocrine tumour, what are the grade and the cell appearance?
  • Was tuberculosis tested for?
  • Is the tissue block kept for further tests?

The answers tell you where the plan stands firm and what is still being checked.

Frequently asked questions

What does it mean that small bowel cancer is four diseases?

Four different cell types can grow into a tumour in the small bowel. They are gland-forming cancer, neuroendocrine tumour, lymphoma and GIST. Each has its own tests, staging method and treatment, so the first job is to name the type from tissue.

What is the MMR test, and why is it done on every gland-forming cancer?

It checks whether the tumour cells can repair their own DNA copying errors. A tumour that cannot is called MMR-deficient. This result can open the way to immunotherapy, and it can point to an inherited condition in the family.

What is HER2 in a small bowel tumour?

HER2 is a protein on the surface of some cancer cells. When a tumour carries too much of it, drugs that target HER2 may help in spread disease. The test is usually sent when the cancer has spread.

What is the grade of a neuroendocrine tumour?

The grade tells you how fast the cells are dividing. It comes from a stain called Ki-67 and a count of dividing cells. The pathologist also says whether the cells look well formed or poorly formed, and this matters as much as the grade.

Can a biopsy tell GIST from lymphoma?

Yes, in most cases. A small set of stains separates the four kinds. Lymphoma lights up for blood-cell markers, and GIST lights up for KIT and DOG1. A pathologist who sees many such tumours gives the most reliable answer.

Why is tissue tested for tuberculosis in India?

Gut tuberculosis can look like a tumour on scans and on a small biopsy. Sending fresh tissue for TB tests avoids calling a treatable infection a cancer, or the other way round.

Do I need a second look at my slides?

If the report is unclear or the type is in doubt, a second review is reasonable. Choose a pathologist who sees these tumours often. Your surgeon can arrange it and bring the slides to the tumour board.

Related pages

For the full range of small bowel tumour care, start at the small bowel cancer treatment page. For questions before you travel, call +91-63555-64601.

Where Dr Harsh Shah sees patients and operates

Dr Harsh Shah — Dr. Jivraj Mehta Hospital, Vasna, Ahmedabad
Dr. Jivraj Mehta Hospital, Dr Jivraj Mehta Marg, Vasna, Ahmedabad 380007.
Consultations, review of reports and scans, operations and follow-up. OPD Monday to Saturday, 9 am to 5 pm.
Appointments: +91-63555-64601 · +91-63590-11009 · Hospital 079-2663 6363
Directions to the hospital · WhatsApp +91-63555-64601

Did your tissue report use words you could not follow, such as grade, MMR or KIT, and did nobody explain them? Bring the report to Dr Harsh Shah. He will tell you which kind of small bowel tumour it names and what each line changes in your plan. Call, or send a message on WhatsApp. Call +91-63555-64601 Ask on WhatsApp

Rate this post

Get health updates from Dr Harsh Shah on WhatsApp

Swasth Parivar: every week, practical advice on recovery, diet and warning signs. No advertising. Stop any time.

Your number is used for these updates and for the clinic to reach you. It is never sold or passed on. To stop, reply STOP on WhatsApp.

Dr. Harsh J Shah
Dr Harsh Shah, Gastro, Cancer & Laparoscopic Surgeon, Ahmedabad
Privacy Overview

This website uses cookies so that we can provide you with the best user experience possible. Cookie information is stored in your browser and performs functions such as recognising you when you return to our website and helping our team to understand which sections of the website you find most interesting and useful.