What is the cause of degenerative uterine fibroids? Do you know?

What are the causes of uterine fibroids? There is no consensus on the tissue origin of uterine fibroids. Some people believe that they are caused by the proliferation of immature uterine wall smooth muscle cells, while others believe that they are caused by smooth muscle tissue in the uterine blood vessel wall. Let our experts briefly introduce the causes of uterine fibroids to you! I hope it will be helpful to you!

Degeneration is mainly caused by various reasons. The main reason for degeneration is insufficient blood supply to the local uterine fibroids, which is usually unrelated to clinical symptoms.

(1) Various types of denaturation:

① Hyalinization: Hyalinization is also called transparent degeneration, which is the most common degeneration of fibroids. The fibroid tissue becomes edematous and soft, the muscle fibers degenerate, the vortex or woven structure disappears, and merges into a glassy transparent body. Since hyalinization often occurs in the connective tissue of the fibroid, this degeneration is more obvious in fibroids with more fibrous connective tissue. Under the microscope, wide bands of transparent connective tissue can be seen in the fibroid, and regional cystic changes may occur; tissue necrosis and lack of structure can also be seen.

② Cystic change: As the hyaline change of uterine fibroids continues to develop, the muscle cells liquefy and cystic change may occur. At this time, the uterine fibroids become soft and difficult to distinguish from pregnant uterine or ovarian cysts. Cystic cavities of varying sizes appear in the fibroids, and several cystic cavities may also merge into a large cavity, with jelly-like and mucous-like substances accumulated inside. The inner layer of the cyst wall is not covered with epithelium, and the degenerative area on the cut surface is cotton-like and of varying sizes. The fluid in the cystic cavity is colorless or bloody. Under the microscope, the cystic change area is stained light blue and cloudy, and small clusters of muscle cells can be seen to remain. There may also be muscle cell hyperplasia around the degenerated muscle cells.

③ Red degeneration: more common during pregnancy or the postpartum period, red degeneration is actually a special type of necrosis of myoma, and the mechanism of occurrence is unclear. It may be that the small blood vessels in the myoma undergo degeneration, causing thrombosis or hemolysis, and hemoglobin infiltrates into the myoma. The cut surface is dark red like half-cooked beef, with a fishy smell, soft texture, and the vortex structure disappears. Under the microscope, it can be seen that the tissue is highly edematous, the small veins in the tumor body have thrombosis, the blood vessels are dilated and congested, there is extensive bleeding and hemolysis, the muscle cytoplasm is lightly stained, the outline is unclear, the muscle cells are reduced, the nucleus often dissolves and disappears, and there are more fat globules deposited.

④ Fatty degeneration: Generally, the lesions are small, and small fat particles can be seen in a few cases. This is mainly due to the increase of fat particles in the myoma cells. Under the microscope, vacuoles are seen in the myocytes, and fat staining is positive. The cause of this may be the metaplasia of the myoma stroma into fat tissue, or the infiltration of fat tissue. When all the fat in the myoma turns into yellow fat, it is called lipoma, but it is extremely rare.

⑤ Calcification: It is more common in subserosal fibroids with small pedicles and insufficient blood supply, as well as fibroids in postmenopausal women. It is more common in fat degeneration and further saponification, decomposition into triglycerides, and then combined with calcium salts. Therefore, fibroid calcification is deposited in the form of phosphoric acid and phosphate in the fibroids, which is as hard as stone. X-rays can clearly see the shadow of calcification. Under the microscope, the calcification area can be seen as layered deposition, round, and with dark blue fine particles.

⑥ Infection and suppuration: Uterine fibroid infection is more common in patients with submucosal fibroids protruding from the uterine or vaginal opening, and subserosal fibroid infection is seen in hematogenous or adjacent organ infection spread. Intramural fibroid infection is more common after cystic degeneration. Submucosal fibroid infection is accompanied by local necrosis, ulceration and mucosal shedding. Bacteria retrogradely enter the uterine cavity and coexist with endometritis and salpingitis.

⑦ Malignant transformation: The malignant transformation of fibroids is mainly sarcomatoid transformation, with an incidence of 0.4% to 1.25%. Sarcomatoid transformation is more common in intramural fibroids, more common in women aged 40 to 50, and less common in those under 30. Malignant transformation should be considered first if the fibroids grow rapidly in a short period of time or are accompanied by irregular bleeding. After the fibroids become malignant, the tissue becomes soft and brittle, the cut surface is grayish yellow, delicate, like raw fish meat, and the boundary with the surrounding tissue is unclear. Under the microscope, smooth muscle cells can be seen to proliferate, with disordered arrangement, disappearance of the vortex structure, and cell atypia.

The above is the cause of uterine fibroids briefly introduced by the experts. I believe you already know it. If you have any questions about uterine fibroids, please consult our online experts. We will serve you wholeheartedly!

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