The causes of different types of uterine fibroids. Can uterine fibroids cause irregular bleeding?

There are many types of uterine fibroids, and for different types of uterine fibroids, it has its own pathological characteristics. Knowing these can give you a clearer understanding of uterine fibroids. This is very helpful for having a correct attitude towards uterine fibroids. Below we will introduce the specific situation of the pathological characteristics of uterine fibroid classification.

① Intramuscular myoma: Intramuscular myoma is also called intramyometrial myoma. It is located in the myometrium and is surrounded by normal myometrium. The boundary between the myoma and the myometrium is clear. The myometrium squeezed around the myoma is usually called a pseudocapsule. This type of myoma is the most common, accounting for 60% to 70% of the total number of myomas. Myomas are usually single or multiple, with different sizes. Small ones, such as rice grains or soybeans, will not change the shape of the uterus; large ones can increase the uterus or change the shape of the uterus, making it irregularly protruding, and the uterine cavity is often deformed.

② Subserous myoma: When the intramural myoma of the uterus grows to the serosa layer on the surface of the uterus, so that the surface of the myoma is only covered with a small amount of muscle wall and serosa, it is called a subserous myoma. When the myoma continues to grow under the serosa, only one pedunculated myoma connected to the uterine wall is formed. The myoma grows on both sides of the uterus and in the broad ligaments on both sides of the uterus. (Intraligamentary myoma), this type of myoma often compresses the nearby ureters, bladders and iliac blood vessels, causing corresponding symptoms and signs. Pedicled myomas can be twisted. Due to obstruction of blood transport, the myoma pedicle breaks and falls off in the pelvic and abdominal cavities, and the tumor necroses. If the fallen myoma adheres to adjacent organs such as the greater omentum and intestinal membrane to obtain blood supply, it is called a parasitic myoma or a wandering myoma. Subserous myoma accounts for 20% to 30% of the total number of myomas. Due to the protrusion of the fibroids, the uterus becomes larger, irregular in shape, uneven in surface, and nodular. Subserosal fibroids can touch any part of the uterus and are movable solid tumors. Broad ligament fibroids touch the uterus and have limited mobility.

③Submucosal fibroids: Submucosal fibroids (submucousmyoma) are intramural fibroids that grow in the direction of the uterine cavity in order to approach the uterine cavity. The surface is covered with endometrium, which is called submucosal fibroids. This type of fibroid protrudes from the uterine cavity and can change the shape of the uterine cavity. Some fibroids are only called pedunculated submucosal fibroids, which are connected to the uterine wall. This type of fibroid causes reflex uterine contractions in the uterine cavity, like a foreign body. Due to gravity, the fibroids gradually move down to the internal cervical os, and eventually the pedicle is elongated, and the fibroids are gradually squeezed at the external cervical os or vaginal opening. This type of fibroid accounts for about 10% of the total. Since the fibroids are located in the uterine cavity, the uterus mostly grows uniformly. Due to the traction of the fibroids and insufficient blood supply to the fibroid pedicles, mild inversion and endometrial bleeding, necrosis and infection on the surface of the fibroids can occur, leading to irregular vaginal bleeding and increased secretions. There are usually multiple types of uterine fibroids. The above-mentioned fibroids can occur simultaneously in the same uterus, which is called multiple uterine fibroids.