An endometrial polyp is a noncancerous (benign) growth that projects from the lining of the uterus into the cavity of the uterus. The lining is called the endometrium. A polyp is made of the same two components as the normal lining: endometrial glands and supporting tissue. In a polyp, too many of these components are present in one place, and they are arranged differently.
Polyps may be attached by a narrow stalk or sit on a broad base. They range from a few millimeters to several centimeters, and a person may have one or several. They are common. Depending on the group studied and how they are looked for, polyps are found in somewhere between 8 and 35 percent of women, and they become more common with age.
Most endometrial polyps are benign. A small proportion contain precancerous changes or cancer, which is why they are examined carefully and usually removed. This article will help you understand what this diagnosis means on your pathology report, what each term means, and why it matters for your care.
Polyps form when a small area of the lining grows more than the tissue around it. Estrogen drives the growth of the lining, so anything that increases estrogen exposure or reduces the balancing effect of progesterone makes a polyp more likely.
Polyps are not caused by infection, are not contagious, and are not inherited in most cases.
Many polyps cause no symptoms and are found incidentally during imaging or surgery for another reason. When symptoms occur, bleeding is by far the most common.
A polyp is usually suspected before surgery. Ultrasound may show a focal thickening of the lining, and a saline infusion sonohysterogram, in which fluid is placed in the uterus during the scan, outlines a polyp more clearly. Hysteroscopy, in which a camera is passed into the uterus, allows the polyp to be seen directly and removed at the same time.
A pathologist makes the final diagnosis by examining the tissue under a microscope; how the tissue was obtained matters more than it might seem. An endometrial biopsy or a curettage performed without a camera samples the lining blindly, and a polyp can be missed entirely or come out in pieces. Reports often say fragments of endometrial polyp for this reason.
This matters because a fragmented polyp cannot always be assessed completely. Your doctor may recommend hysteroscopy so the polyp can be removed whole and examined in full. This applies if imaging shows a polyp but only fragments reach the laboratory, or if bleeding continues after a normal result.
An endometrial polyp is a localized overgrowth of endometrial glands and supporting tissue projecting from the lining of the uterus. Pathologists rely on a combination of features rather than any single one.
Most polyps are reported as endometrial polyps. Some have features that earn a more specific name, which may appear in your report.
It can, but it is uncommon, and the risk varies widely depending on your situation. Pooled results from many studies give a useful picture.
Other factors that raise the likelihood include age over 60, a polyp larger than about 1.5 cm, tamoxifen use, excess body weight, high blood pressure, and diabetes. Precancerous change short of cancer, meaning atypical hyperplasia or endometrioid intraepithelial neoplasia, is found somewhat more often than cancer itself.
This is why the pathologist examines the whole polyp rather than a representative piece, and why polyps are usually removed rather than watched. If the pathologist finds cancer or a precancerous change, the report names it directly. A report that says endometrial polyp with no further qualification means the pathologist looked for those changes and did not find them.
Removal through a hysteroscope, called hysteroscopic polypectomy, is the standard treatment. The camera lets the polyp be seen and removed completely, which relieves symptoms and provides the whole polyp for examination. Blind curettage is less reliable, because a polyp can be missed or only partly removed.
Not every polyp has to be removed. A small polyp causing no symptoms in someone before menopause may reasonably be watched. Up to a quarter of these resolve on their own within a year, particularly those under 1 cm. Removal is generally recommended when there is bleeding, when the polyp is large, or when you have gone through menopause. It is also recommended if you take tamoxifen or are trying to conceive.
Polyps can come back after removal, more often when several were present. Recurrent bleeding after a polypectomy is worth reporting rather than assuming the problem was dealt with.
They may. Polyps are found more often in people investigated for difficulty conceiving than in the general population. A polyp sitting in the cavity of the uterus may interfere with an embryo settling into the lining, or with sperm reaching the fallopian tube.
Removing a polyp before fertility treatment is commonly recommended, and studies of polypectomy before insemination or IVF have reported better pregnancy rates afterward. If you are planning fertility treatment and a polyp has been found, this is worth raising with your specialist.
Your report will describe the lining outside the polyp as well as the polyp itself, and that description matters as much as the diagnosis of the polyp.