Etiology
During the embryonic period, the mesodermal fissures in the venous plexus fuse to form large primitive lymphatic sacs that drain into the central venous system, which later degenerate or develop into a system of lymphatic vessels parallel to the veins. If the primitive lymphatic sacs are not connected to the venous system, cystic lymphangiectasia may occur; if they are not connected to the main lymphatic system, spongy lymphangiectasia may occur; if a small number of lymphatic sacs are separated during the formation of the lymphatic system, simple lymphangiectasia may form. Because of the earliest lymphatic formation of the jugular vein bursa. Because of the largest volume, cystic lymphangiectasia is most common in the neck.
Clinical manifestations
1. Cystic masses in the posterior cervical triangle are characterized by spreading to the four blows (above and below the clavicle, floor of the mouth, paratracheal esophagus and mediastinum), and the boundaries are often unclear. Most often seen in infants and young children. It is huge at birth and can grow gradually.
2. Cystic tumors are soft, generally non-compressible, and can transmit light. The surface skin is normal and not adherent.
3.The contents are yellowish transparent or celiac, occasionally with blood. Microscopically, a large number of lymphocytes containing cholesterol crystals can be seen.
4.When the cystic tumor involves the floor of the mouth, tongue or pharynx, there may be speech, breathing or swallowing disorders. If the cystic tumor is located on the clavicle, there may be movement disorder or muscle atrophy by compression of the brachial plexus. Sometimes the trachea is displaced by pressure.
Differential diagnosis
1. Expecting self-healing
Smaller lymphangioleiomas that do not affect function and are not aesthetically pleasing can be left untreated. Because some lymphangiectasias have a tendency to fade away naturally. For those who have extensive lesions but no signs of respiratory or swallowing difficulties and other serious complications, they can be left untreated for two years and then treated if they do not subside or increase in size.
2.Injection therapy
In the past, the method of local injection of sclerotherapy for lymphangioleiomyomatosis had no obvious effect. In recent years, local injection therapy with the antitumor drug bleomycin has achieved more satisfactory results, with complete regression and significant reduction of up to 70%. It may be that the therapeutic purpose is achieved by the dual action of inhibiting the growth of endothelial cells of lymphatic vessels and the chemical stimulant to fibrosis of mesenchyme. Histologically, it is less effective in the more mesenchymal types such as simple and cavernous lymphangioleiomas and more effective in the mesenchymal and types such as cystic hydatid tumors. This has been shown to be true in practice.
Since injection therapy is easier and less destructive to tissues, it can avoid serious complications that may occur due to surgery, and surgery is often difficult to remove completely, so it can be the first choice for cystic lymphangiectasia.
3.Surgical treatment
Although surgical resection is still the main treatment for lymphangioleioma, it is not recommended to operate on any type of lymphangioleioma without any indication. Surgery is only indicated when lymphangiectasia in the neck has a tendency to expand into the mediastinum and chest cavity, may cause respiratory distress, affects eating, and is ineffective with injection therapy. Lymphangioleioma complicated by infection should not be operated, and the infection must be controlled first. Intracapsular hemorrhage is not a contraindication to surgery.
The actual extent of cystic lymphangiectasia often exceeds the original estimation, and it is often difficult to completely remove the lesion during surgery, which requires careful dissection of important nerves and blood vessels in the neck. The surgery requires careful dissection of important nerves, blood vessels and other structures in the neck to prevent facial nerve palsy and damage to the lingual, recurrent laryngeal and phrenic nerves that may cause respiratory distress and hoarseness. For the remaining cyst wall, 0.5% tincture of iodine can be applied to destroy the endothelial cells to prevent recurrence.
Treatment.
1. Expecting self-healing
For small and limited lymphangioleiomas that do not affect the function and do not affect the beauty, they can be left untreated. This is because some lymphangiectasias have a tendency to fade away naturally.
2.Injection therapy
In recent years, local injection therapy with the antitumor drug bleomycin has achieved more satisfactory results, with complete regression and significant reduction up to 70%.
3.Surgical treatment
Although surgical resection is still the main treatment method for lymphangioleioma, it is not recommended to operate on any type of lymphangioleioma without any evidence. Surgery is only indicated when lymphangiectasia in the neck has a tendency to expand into the mediastinum and chest cavity, may cause respiratory difficulty, affects eating, and is not treated by injection. Lymphangioleioma complicated by infection should not be operated, and the infection must be controlled first. Intracapsular hemorrhage is not a contraindication to surgery.
The actual extent of cystic lymphangiectasia often exceeds the original estimation, and it is often difficult to completely remove the lesion during surgery, which requires careful dissection of important nerves and blood vessels in the neck. The surgery requires careful dissection of important nerves, blood vessels and other structures in the neck to prevent facial nerve palsy and damage to the lingual, recurrent laryngeal and phrenic nerves that may cause respiratory distress and hoarseness. For the remaining cyst wall, 0.5% tincture of iodine can be applied to destroy the endothelial cells to prevent recurrence.