Polyp and fibroid are terms frequently used to describe abnormal growths within the uterus, though they are distinct conditions. Both are typically non-cancerous and can cause similar symptoms. The primary difference between a polyp and a fibroid lies in the specific tissue from which each growth originates and its location within the uterine structure. Understanding their composition and placement helps explain why their symptoms and treatments differ.
Uterine Polyps Composition and Location
Uterine polyps, also known as endometrial polyps, form from an overgrowth of the endometrium, the soft, inner lining of the uterus. Polyps develop when this tissue proliferates excessively, resulting in growths that are generally soft and fleshy. They consist primarily of glandular tissue and a fibrous core called stroma.
Polyps are classified based on how they attach to the uterine wall. Some are sessile, having a broad, flat base, while others are pedunculated, connected by a slender stalk or pedicle. Endometrial polyps grow inside the uterine cavity and range in size from a few millimeters to several centimeters. Cervical polyps are a related type that originates from the epithelial cells of the cervix.
Uterine Fibroids Composition and Location
Uterine fibroids are solid tumors composed of smooth muscle cells and connective tissue. They develop within the myometrium, the thick, muscular wall of the uterus. This composition results in a denser, firmer texture compared to polyps.
Fibroids are categorized based on their location within the uterine wall. Intramural fibroids are the most common type, developing entirely within the muscular wall. Subserosal fibroids grow on the outside surface of the uterus and may extend into the pelvic cavity. Submucosal fibroids are located beneath the endometrium and protrude into the uterine cavity, often causing significant symptoms despite their size.
Fibroids vary dramatically in size, from microscopic to masses large enough to fill the abdominal cavity, a key distinction from typically smaller polyps. Like polyps, some fibroids can be pedunculated, growing on a stalk either inside (submucosal) or outside (subserosal) the uterus. Hormones, particularly estrogen and progesterone, influence fibroid growth, which is why they commonly develop during childbearing years.
Practical Differences in Symptoms and Treatment
The differing tissue origins and locations of these growths lead to variations in the symptoms they produce and their management. Uterine polyps are often associated with irregular or light bleeding, such as spotting between periods or after menopause. They may also cause heavy menstrual flow or issues with fertility if they obstruct the fallopian tubes or uterine cavity.
Uterine fibroids, particularly intramural and submucosal types, are commonly linked to heavy, prolonged menstrual bleeding and severe pelvic pain. Since fibroids can grow much larger than polyps, they frequently cause pressure-related symptoms. These symptoms include the feeling of pelvic fullness, frequent urination from bladder pressure, or constipation from rectal pressure. Submucosal fibroids are known to cause significant bleeding even when small.
Treatment Options
Treatment for polyps is often straightforward removal through hysteroscopic polypectomy. This procedure uses a thin instrument to visualize and remove the growth from inside the uterus.
Fibroid treatment is more varied and depends on the growth’s size, location, and symptom severity. Options range from watchful waiting and hormone-based medications to surgical procedures. These procedures include myomectomy, which removes fibroids while preserving the uterus, or, in extensive cases, a hysterectomy.