The four main types of uterine fibroids: explained


When receiving a diagnosis of fibroids, also called leiomyomas or just myomas, there’s another term tacked onto the fibroids. They can be intramural, subserosal or submucosal. Subsurosal and submucosal fibroids can appear as pedunculated fibroids. As part of our mission to help women to become more informed and educated toward managing their own uterine fibroids — together with medical professionals – we will now explain the meaning of these terms. 

The first three classifications in our list of fibroids indicate their location. In order to better understand and pinpoint location, let’s just quickly mention a few more terms. The uterus has three different layers: 

  1. The endometrium is the inner layer that lines the uterus. 
  1. The myometrium is the middle layer. This is also the thickest of the three uterine layers. 
  1. The perimetrium is the outer layer. 
  1. The serosa is the outside surface of the uterus. 

Intramural fibroids are located within the muscular walls of the uterus, the myometrium. They can cause any of the symptoms that any other fibroid can cause, including heavy bleeding, chronic pain and heavy menstrual cramping, frequent urination, constipation, back pain, pelvic pain and bloating. 

Subserosal fibroids are located near the outer layer of the uterus, the serosa. Subserosal fibroids don’t bother the environment in the interior of the uterus, but larger fibroids in this area can cause pain by pressing against neighboring organs. Similarly, they can also cause frequent urination by pushing against the bladder as well as constipation by putting pressure on the rectum. Fibroids growing closer to the cervix may be more likely to create pain or even bleeding during sexual penetration. 

Submucosal fibroids grow from interior layer of the uterus, the mucosa. These can protrude into the interior of the uterus. These growths can create more fertility havoc at smaller sizes than other fibroids and are the first to cause excessive menstrual bleeding and pain. 

Predunculated fibroids are fibroids that grow on a stem-shaped base, widening into a more “blob-shaped” fibroid. They can grow into the uterine cavity or outward from the outer uterine wall. The additional complication that can come with predunculated fibroids is the possibility of them twisting on their stem, thereby cutting off their own blood supply, and this can become extremely painful. 

While scientists have found factors that contribute to the formation of uterine fibroids, no reason has yet been found to determine why a fibroid would form in one particular area of the uterus rather than another. 

With symptoms running the full range from completely unnoticeable to absolutely debilitating, fibroids pose quite a challenge for both the sufferer and the medical community. It’s vital to find a doctor you trust and with whom you feel comfortable and to monitor your situation. In situation where symptoms pose little to no decline in your quality of life, they can often be left untreated. However, if and when pain and bleeding reach a problematic level, treatment options are fortunately expanding. Ask your doctor what solution options fit your needs. And feel better!