Gallbladder polyps: who gets watched, and who gets operated on

When a health checkup reports a gallbladder polyp, patients divide into two reactions. Some worry that it will turn into cancer. Others, seeing no symptoms, treat it as nothing. Gallbladder polyps are indeed found incidentally at checkups very often, and a substantial proportion never cause a problem. That does not mean every one of them is managed the same way. For some patients periodic ultrasound is enough; others need further imaging, or surgery.

Understanding the difference starts with knowing that “gallbladder polyp” does not name a single disease.

Two different things under one word#

Any lesion protruding inwards from the inner wall of the gallbladder is called a polyp, and their nature can differ entirely. The commonly found kind is the cholesterol polyp: cholesterol from the bile accumulating on the gallbladder wall until it looks like a polyp. That is a different thing from a tumour formed by cells actually multiplying. There are also true polyps, such as adenomas, made by genuine cell proliferation, and in some of those the possibility of malignant change has to be considered.

The problem is that from the moment a polyp is found at a checkup, telling those two apart perfectly is not easy. So we look at the size and number of the polyp on ultrasound, its shape, and changes in the gallbladder wall, and judge the risk from those. If there is a previous scan, whether the size has changed against it is important information too. The question is not simply whether a polyp is present, but what it looks like and how it is changing.

Size, and what sits around it#

One of the important criteria among these is size. Generally, if a polyp is small and shows typical benign features, it is often watched for a period with ultrasound. Conversely, the larger it becomes, the more carefully the possibility of a neoplastic lesion has to be considered. A polyp around 10 mm in particular can be an important criterion in judging whether to operate.

But a single number does not decide surgery on its own. Even where the size is small, further evaluation is needed if the polyp is sessile, with a broad base attached to the wall, or if the gallbladder wall has thickened, or if it keeps growing on follow-up.

The patient's own circumstances are weighed alongside. Where there are factors that can raise risk — older age, or other gallbladder disease such as stones present at the same time — the size and shape of the polyp have to be judged together with them. That is why, with a gallbladder polyp of the same size, follow-up is appropriate for one person and more active investigation or treatment is needed for another.

Why the operation removes the gallbladder#

If surgery is judged necessary because of a gallbladder polyp, what is performed is not the excision of the polyp but a cholecystectomy — removal of the whole gallbladder. This is different from the way a polyp is taken from the stomach or the colon with an endoscope and sent for histology. Structurally, a polyp cannot be removed from the gallbladder on its own, so when there is a possibility of malignancy or treatment is required, the approach is to take the gallbladder with it.

That is what makes the decision consequential in both directions: not removing a gallbladder unnecessarily, while not missing a lesion that needs treating.

Symptoms will not tell you#

What patients should be careful of here is the thought that it must be fine because there are no symptoms. Most gallbladder polyps cause no particular symptoms. Even where there is pain in the right upper abdomen or poor digestion, it is difficult to conclude that a polyp is necessarily the cause. So rather than judging the risk of a polyp by the presence or absence of symptoms, what has to be examined is the features confirmed on imaging and how they change over time.

What to take off the report#

If a checkup finds a gallbladder polyp, the first thing to confirm on the result sheet is the size. If possible, check how many there are and what shape they are, and if there is a previous ultrasound, compare against the old size. After that, set a follow-up interval appropriate to the present state and confirm the change.

1. The size, in millimetres, as reported.
2. The number of polyps, and whether any is described as sessile or broad-based.
3. Whether the gallbladder wall is described as thickened, and whether stones are also present.
4. The size on the previous scan, if there is one.
5. The date of the next check.

If you use a different screening centre each year, keeping the previous results is particularly helpful. Having the earlier record is what makes it possible to tell whether this is a newly appeared polyp or one that has not changed in several years.

Finding a gallbladder polyp is not a reason to worry immediately about cancer, or to think first about surgery. Nor is it a reason to skip later checks simply because it is small. What matters with a gallbladder polyp is not only the size at the moment it is found, but what shape it has and how it changes as time passes. Picking out in good time the polyp that needs treatment, while avoiding the operation that is not needed — that is the most important principle in managing them.