Uterine fibroid

What it means

The uterus is made largely of smooth muscle, and a fibroid is a benign tumor that forms when a cluster of that muscle tissue grows into a firm, rounded mass. Fibroids are sometimes called leiomyomas, their medical name, and they are one of the most common findings in the female pelvis, particularly during the reproductive years. A person can have a single small fibroid or multiple fibroids of different sizes, and many are discovered incidentally on a scan done for an unrelated reason, since they frequently cause no symptoms whatsoever.

Why it appears on a CT or MRI report

The report typically records the number of fibroids, their size in centimetres, and their location relative to the uterine wall: submucosal (bulging into the uterine cavity), intramural (within the muscular wall itself, the most common location), or subserosal (bulging outward from the outer surface). MRI is particularly good at mapping fibroids precisely, which matters if treatment is being planned. The radiologist may also comment on whether a fibroid is degenerating, meaning it has outgrown its blood supply and developed internal changes, which is a benign process but can occasionally cause pain.

What it usually means

The overwhelming majority of fibroids are benign and stay that way; a fibroid turning cancerous is rare. Small fibroids, especially ones tucked within the muscular wall or outer surface, often require nothing more than periodic reassurance that they are not growing. Larger fibroids, or ones bulging into the uterine cavity, are more likely to cause heavy or prolonged periods, pelvic pressure, or, less commonly, fertility challenges, and these are the ones most often discussed for treatment. Options range widely depending on symptoms, size, location, and whether future pregnancy is desired, including medication to manage bleeding, a minimally invasive procedure to shrink the fibroid's blood supply, or surgical removal.

When to follow up

Share the report with your gynecologist, who will weigh the size, location, and your symptoms and fertility goals to decide whether monitoring or treatment makes sense. Fibroids without symptoms are frequently just followed with routine pelvic exams or occasional ultrasound. Reach out sooner if you notice heavy bleeding that soaks through pads or tampons quickly, bleeding between periods, new or worsening pelvic pain, or pressure symptoms like frequent urination, since these can guide the timing of treatment.

A plain-language way to picture it

Think of the uterine wall as a well-toned muscle, and a fibroid as a small, firm knot that forms within that muscle, much like a knot that can develop in a tense shoulder. It is made of the same tissue as the muscle around it, just bunched into a denser lump. Most knots stay small and quiet; some grow large enough to be noticed and worked on, but they are not spreading or invasive — they are simply an overgrown patch of normal tissue.