Pulmonary hydatid disease

Introduction to pulmonary hydatid disease Pulmonary hydatid (pulmonary hydatid cyst, pulmonary hydatid cyst, pulmonary hydatid cyst) is caused by parasitic larvae of the echinococcosis (canine aphid) in the lungs, which is more common in the lungs. Parasitic disease, zoonosis. The disease is most common in animal husbandry areas, almost all over the world, especially in Australia, New Zealand, South America, etc. China is mainly distributed in Gansu, Xinjiang, Ningxia, Qinghai, Inner Mongolia, Tibet and other provinces. basic knowledge The proportion of illness: the incidence rate is about 0.002%-0.007% Susceptible people: no special people Mode of infection: digestive tract spread Complications: mediastinal abscess measles anaphylactic shock

Cause of pulmonary echinococcosis

Parasitic infections (30%):

The terminal host of Echinococcus granulosus, the adult parasitic in the small intestine of the dog, the eggs are discharged with the feces and contaminated food. After eating (human, sheep, pig, cattle), the egg shell is digested by the gastric juice in the upper digestive tract and hatched into larvae. That is, the six hooks, after passing through the mucosa of the digestive tract into the blood, to the portal system (mesomembranous, omentum and liver), most of the sputum stay in the liver (about 75% to 80% 0 a small amount of six hooks through the liver Small circulation to the lungs (about 8% to 15%) and other organs, such as mesentery, omentum, spleen, pelvis, muscle, subcutaneous tissue.

Other factors (25%):

After entering the lungs, the six hooks gradually develop into hydatid cysts, which grow to about 1-2 cm in about half a year. Due to loose lung tissue, abundant blood circulation and negative pressure in the chest, the growth rate of the six hooks in the lungs is higher than that. The liver and kidney are fast, the average annual growth to 1 to 2 times the original volume, up to 2 ~ 6cm, the largest cyst can reach 20cm, the cystic fluid weighs more than 3000g, the hydatid cyst contains the outer capsule and the inner capsule, the inner capsule is The inherent cyst wall of the hydatid cyst is only 1mm thick, but the pressure is as high as 13.3~40kPa (100~300mmHg). It is easy to break. The inner capsule can be divided into inner and outer layers. The inner layer is the germinal layer, which is very thin and secretive. The transparent capsule liquid produces many ascospores and parasitic head segments. If it falls into the cyst cavity, it becomes a worm-covered sand. The outer layer is cell-free, multi-layered, translucent, milky white, elastic, and looks like a powdery skin. The outer capsule is A fibrous envelope formed by the reaction of human tissue to the inner capsule surrounds the entire inner capsule and is about 3 to 5 mm thick. The inner and outer capsules are potential cavities, no liquid or gas, and no adhesion.

80% of pulmonary hydatid cysts are peripheral type, the right lung is more than the left lung, the lower lobe is more than the upper lobe, and the right lung has a slightly more blood flow, which is closer to the liver. There is a rich lymphatic communication between the two. It is more common in the right lung. The cysts are mostly single, accounting for 65% to 75%. The multiples are usually 2 to 3, one or both sides, about 17% to 22%, and other parts of the cyst, lung, liver. Concurrency is the most common, accounting for 13% to 18%.

The pathological changes of pulmonary hydatid disease, in addition to the cyst itself, are mainly the mechanical compression of the giant cyst to the lungs, causing atrophy, fibrosis or congestion and inflammation of the surrounding lung tissue. >5cm cyst can cause bronchial displacement, stenosis of the lumen, or necrosis of bronchial cartilage, and then break into the bronchi. Superficial pulmonary hydatid cysts can cause reactive pleurisy, huge cysts may also break into the chest, a large number of head joints overflow, forming a number of secondary hydatid cysts. The cyst located in the center occasionally erodes and bleeds through the large blood vessels. A small number of hydatid cysts have calcification. If the cyst breaks into the bronchioles and the air enters between the outer capsules, a variety of X-ray signs can be formed. Infected or ruptured cysts may be combined with the thoracic cavity and mediastinal abscess or empyema. The hepatic hydatid cyst may be connected to the chest or lung or bronchus after rupture, forming a hydatid cyst - bile duct - bronchospasm.

Pulmonary hydatid disease prevention

The main reasons for the prevention of this disease are as follows:

1. Conduct health education in popular areas, check patients, train professionals, establish prevention and control institutions, and conduct prevention and control and scientific research.

2. Strictly control the source of infection, reasonably handle sick animals and their internal organs, and advocate deep burial or incineration. Drugs and dogs should be regularly dewormed, and wild carnivores around the pastures should be killed to eliminate the source of infection.

Pulmonary hydatid complications Complications, mediastinal abscess, measles, anaphylactic shock

1, allergic reactions and echinococcosis transmission, due to various reasons caused by rupture of the hydatid cyst, can cause secondary hydatid infection, because its contents are a foreign trait compared to the body, can cause Urticaria, asthma, eosinophilia and other allergic reactions, if the cystic fluid enters the blood circulation, severe anaphylactic shock or even death may occur.

2, pulmonary hydatid cysts - bile duct - bronchospasm cysts - bile duct - bronchospasm has been infected or ruptured cysts can be combined with chest and mediastinal abscess or empyema, hepatic hydatid cyst may be associated with the chest or lung after rupture, The bronchus communicates to form a pulmonary hydatid cyst - bile duct - bronchospasm.

3, when the lung hydatid sac is broken into the bronchus, it can cough up a lot of liquid and broken sacs.

Pulmonary hydatid symptoms common symptoms dyspnea fever fist cyst inflammation pus

According to the analysis of large group cases in China from 1950 to 1985, pulmonary hydatid disease accounted for 14.81% (2408/16258) of human echinococcosis, more male than female (about 2:1), and children accounted for 25% to 30%, under 40 years old. The majority, the youngest is 1 to 2 years old, the largest is 60 to 70 years old.

From infection to symptoms, the interval is usually 3 to 4 years, or even one or twenty years. Symptoms Due to the size, number, location, and presence or absence of complications, the early cysts are small and generally have no obvious symptoms. They are often detected by physical examination or when chest disease is seen due to other diseases. When the cyst is enlarged to cause compression or inflammation, there are symptoms such as cough, cough, chest pain, and hemoptysis. A huge cyst or near the hilar may have difficulty breathing. If the esophagus is stressed, there is difficulty in swallowing. Side of the lung tip cyst compression brachial plexus and cervical sympathetic ganglia, causing Pancoast syndrome (shoulder shoulder, arm pain) and Horner sign (one eyelid drooping, skin flushing does not sweat). If the cyst breaks into the bronchus, the amount of cystic fluid is large, there is a risk of suffocation, and the ascus and head section overflow, which can form multiple new cysts. Patients are often accompanied by allergic reactions such as skin flushing, urticaria and wheezing, and severe shock. Cyst rupture infection, there are fever, cough and phlegm and other lung inflammation and lung abscess symptoms. A small number of cysts broke into the chest, with fever, chest pain, shortness of breath and allergic reactions.

Most patients have no obvious positive signs, larger cysts can cause mediastinal shift, and thoracic deformities may occur in children. The affected side is percussed with dullness, weak breathing, and there are signs of pleurisy or empyema.

Lung hydatid disease examination

1. Chest X-ray examination is the main diagnostic method for echinococcosis. In the epidemic area of this disease, there is a history of exposure. Most of the chest radiographs can be diagnosed. The early diameter of the cyst is less than 1cm, and only the inflammatory shadows with blurred edges are seen. The diameter >2cm is a clear-cut, sharp-edged circular shadow with a uniform density and a slight lightness, which is lower than the density of the heart and the substantial tumor. It can be 6~10cm when the diagnosis is clear, and the density is close to that of the parenchyma. Hair, there are many, as a liquid cyst, the position of the diaphragm when the inhalation of the diaphragm decreased, the head, the foot diameter increased slightly, when the expiratory diaphragm muscle rose, the transverse diameter is slightly longer and shorter ("hydatid breathing sign"), Large cysts may be lobulated or multi-annular, and the cysts of the lower lungs "sit" on the diaphragm, causing the position of the sputum to drop, or even depression. Sometimes the artificial ventral mediastinum is pushed to the opposite side, and the mediastinum in the lower lobe is affected. The effect is small, and the large cyst at the top of the right liver obviously shifts the heart to the left. This feature is helpful for differential diagnosis. A few cases have atelectasis and pleurisy.

2, laboratory examination: eosinophils increase, often in the 5% ~ 10%, or even up to 20% ~ 30%, directly 0.15 ~ 0.3) × 109 / L. Sometimes cysts and sacs, sacs, or small hooks can be found in cough or pleural fluid.

3. Other diagnostic methods include the echinococcal intradermal test (Casoni test), the hydatid complement test, and the indirect hemagglutination test.

Diagnosis and identification of pulmonary hydatid disease

Diagnosis can be based on medical history, clinical symptoms, and laboratory tests.

Pulmonary hydatid cysts should be differentiated from lung abscess, cavitary pulmonary tuberculosis, pulmonary alveolar infection and congenital peripheral pulmonary cyst. The clinical manifestations of lung abscess are heavier. The lungs on the CT have obvious lung texture and uneven wall thickness. And see no changes in the lacy-like cysts, hollow tuberculosis is generally small, satellite lesions can be seen around; and there are disseminated lesions, lung vesicles combined with infection can be seen in liquid level, the wall is thin and even, the diameter is small, the peripheral lung cyst can be seen The liquid level is flat, the wall is thin, and often combined with bronchopulmonary dysplasia.

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