Lymphangioleiomyomatosis is a disease characterized by abnormal development of the lymphatic vascular system, i.e., a mass consisting of abnormally proliferated lymphatic vessels filled with lymphatic fluid. The growth of the proliferating lymphatic vessels is somewhat restricted and does not have characteristics similar to tumor cell proliferation and metastasis. Lymphangioleiomyomatosis is relatively common, with no significant racial or gender differences, and is most common in children under 10 years of age. The cause of lymphangioleiomyomatosis is not clear. Most scholars believe that lymphatic ducts are formed due to congenital malformation of lymphatic ducts or some other causes such as trauma, inflammation, parasites, etc., which cause lymphatic fluid retention at the site of disease, resulting in lymphatic duct expansion and hyperplasia. Most pediatric lymphangioleiomas are seen in adults due to congenital developmental malformations, trauma, etc. In a study on the etiology of cervical cystic lymphadenoma, it was found that 62% of affected fetuses had chromosomal abnormalities, suggesting that the occurrence of lymphadenoma may be related to the abnormal number of chromosomes or their subtypes in patients. Lymphangioleioma can occur anywhere in the body that contains lymphatic tissue, with approximately 95% occurring in the neck and axilla (about 75% in the neck and 20% in the axilla) and rarely in other areas. Traditionally, lymphangioleiomas are classified into the following three categories: (1) spongy lymphangioleioma: It is the most common type of lymphangioleioma, mainly consisting of large lymphatic sinus cavities, often with fibrous envelope, and is found in the lip, tongue, cheek and neck, etc. The main manifestation is local tissue swelling and deformation. This type of lymphangioleioma cannot be compressed and usually does not invade the skin, but can invade the mucosa and form many villi-like protrusions on the mucosal surface. ( 2) Cystic lymphangioleioma: Also called cystic hydatid tumor. It mainly consists of huge lymphatic cavities visible to the naked eye and is the most common type of lymphangioleioma, mostly found in the neck and axillae, which manifests as cystic pouch fast of different sizes. The lesion is generally well-defined, fluctuating and cannot be compressed, and yellowish fluid can be extracted by puncture. ( 3) Simple lymphangioleioma: also known as capillary lymphangioleioma, it is very rare and consists of small thin-walled lymphatic vessels, commonly found in the proximal part of the limb, which looks like a rice-sized cyst protruding from the skin surface and can flow lymphatic fluid after rupture. The main symptoms of lymphangioleioma Most of the lymphangioleiomas are painless masses with soft texture and fluctuating feeling, and can flow out yellowish fluid after rupture. When the tumor enlarges and presses on the surrounding tissues, or when bleeding, infection, torsion or rupture occurs, corresponding symptoms such as pain, fever, difficulty in breathing, difficulty in swallowing, etc. may appear. The preoperative diagnosis of lymphangioleioma is low, especially if it is located in the body cavity. Imaging and puncture biopsy can improve the diagnosis. Color Doppler ultrasonography is simple and quick, and can determine the location, number, and relationship of the tumor to its surroundings, but is susceptible to certain factors. A typical lymphangioleioma presents as a low-tension amorphous cystic mass with a mass size ranging from 0 . The size of the mass varies from 0.5 cm to several tens of centimeters, and there are bands of echogenic separation within the cyst, forming a typical beehive-like structure. CT is easier to show the relationship between tumor and surrounding organs. The typical CT presentation of lymphangioleioma is: thin-walled, smooth cystic material with uniform density and visible separation within the cyst, and the cystic wall and separation can be enhanced. MRI can clearly show the location, size, shape and scope of tumor, which is the best diagnostic method at present. Interventional aspiration can be performed under ultrasound or CT guidance to extract the cystic fluid from the tumor. If the fluid is plasmacythematous or celiac and contains a large number of lymphocytes, it is highly suggestive of the diagnosis of lymphangioleiomyomatosis. Pathology of lymphangioleioma Lymphangioleioma is characterized histologically by a flattened epithelial layer of endothelial cells and a cystic wall containing interlocking lymphoid tissue, small lymphoid spaces, smooth muscle, and foam cells. Lymphangioleiomyosarcoma is generally considered to be a benign disease, but some scholars consider it to be malignant. For example, lymphangioleiomyosarcoma (endothelial) sarcoma and lymphangioleiomyosarcoma are considered to be malignant lymphangioleiomyosarcoma, which is very rare. Treatment of lymphangioleiomyosarcoma Unlike hemangioma, lymphangioleiomyosarcoma does not disappear automatically, so if it is diagnosed as lymphangioleiomyosarcoma, it should be treated as soon as possible. There are many treatment methods for lymphangioleioma, besides surgery, there are also aspiration of tumor cystic fluid, injection of sclerosing agent after aspiration, heat therapy, radiotherapy and so on. It is generally believed that the treatment method should be decided according to the size and location of tumor, complexity of resection and danger of operation. (1) Surgical treatment: Among various treatment methods, surgical resection is the preferred treatment for lymphangioleioma. Lymphangioleioma has the characteristics of infiltrative growth and high recurrence rate. Therefore, according to the site of occurrence and the scope of involvement, the tumor should be removed completely at one time as far as possible, and if necessary, the affected organs can be partially or completely removed, and the surrounding lymphatic channels can be ligated at the same time to prevent the lymphatic fistula from causing recurrence. (2) Cystic fluid aspiration: aspiration of the fluid inside the tumor can only temporarily relieve the pressure of the tumor on the surrounding tissues or organs, and since the tumor cavity is connected to the lymphatic vessels, recurrence can occur quickly. (3) Sclerotherapy: Injection of OK-432, bleomycin, pinyamycin, fiber sealant, etc. after aspiration of the tumor body fluid can promote inflammatory adhesion of the tumor wall and occlusion of the lymphatic vessels to prevent recurrence, among which the application of fiber sealant has better results and can even avoid surgery. In addition, there are methods such as radiation, laser and heat therapy, but the effect is not very satisfactory. Prevention of lymphangioleiomyelitis Since the exact cause of lymphangioleiomyelitis is not clear, there is no effective means of prevention. However, it is generally believed that the incidence of congenital lymphangiectasia may be reduced by avoiding colds and viral infections during pregnancy, preventing the use of drugs that may adversely affect the fetus, and not being exposed to radiation. The incidence of adult lymphangiectasia can be reduced by paying attention to personal and environmental hygiene, avoiding drug abuse, paying attention to personal protection when working in harmful environments, and improving physical fitness and resistance to disease through appropriate exercise.