Lung nodules

Introduction to pulmonary nodules Sarcoidosis is a multi-system, multi-organ granulomatous disease of unknown etiology that has attracted widespread attention in the country. Often invaded the lungs, bilateral hilar lymph nodes, eyes, skin and other organs. Its chest invasion rate is as high as 80% to 90%. The disease is distributed in the world, and the incidence rate in Europe and the United States is high, and the ethnic groups in the East are rare. More common in 20 to 40 years old, women are slightly more than men. More than 560 cases have been reported in China (1987). basic knowledge Sickness ratio: 0.0001% Susceptible people: no special people Mode of infection: non-infectious complication:

Cause of pulmonary nodules

Cause: It is not clear. Observations on infectious factors (such as bacteria, viruses, mycoplasma, fungi, etc.) have not been confirmed. Genetic factors have also been studied and failed to confirm. In recent years, some authors have found that the positive rate of Mycobacterium tuberculosis DNA is 50% in patients with sarcoidosis by PCR. It is suggested that sarcoidosis is the result of mycobacterial invasion, but many experiments have not confirmed this argument. Most people believe that cellular immune function and humoral immune dysfunction are important pathogenesis of sarcoidosis. Alveolar macrophages (Am) and T4 cells are activated by stimulation of certain (some) nodulation antigens. Activated Am releases interleukin-1 (IL-1), a potent lymphokine that stimulates lymphocytes to release IL-2, doubling T4 cells and acting as a lymphokine Under the B lymphocyte activation, release of immunoglobulin, autoantibodies function. Activated lymphocytes release monocyte chemotactic factors, leukocyte inhibitory factors, and macrophage migration inhibitory factors. Monocyte chemokines cause monocytes in the surrounding blood to continuously accumulate in the alveolar interstitial, and the concentration in the alveolus is about 25 times that of blood in sarcoidosis. Under the action of many unknown antigens and mediators, T lymphocytes, monocytes and macrophages infiltrate into the alveoli, forming an early stage of sarcoidosis, the alveolitis stage. With the development of lesions, the cellular components of alveolitis are decreasing, and the epithelioid cells derived from macrophages are gradually increasing. Under the action of the granuloma-inciting factor synthesized and secreted, it is gradually formed. Non-caseal nodular granuloma. In the later stage, fibronectin (Fn) released by macrophages can attract a large number of fibroblasts (Fb) and adhere them to the extracellular matrix, together with fibroblast growth factor secreted by macrophages ( Growth factoroffibroblasts (GFF), which promotes an increase in the number of fibroblasts; at the same time, the surrounding inflammation and immune cells are further reduced and disappear, resulting in extensive fibrosis of the lungs.

Pulmonary nodule prevention

Pulmonary nodule complications Complication

Pulmonary nodule symptoms common symptoms chest tightness and weakness

Symptoms and signs vary depending on the onset of illness and the number of organs involved. There are no obvious symptoms and signs in the early stage of thoracic sarcoidosis. Sometimes coughing, coughing a small amount of sputum, occasionally a small amount of hemoptysis; may have fatigue, fever, night sweats, loss of appetite, weight loss and so on. Chest tightness, shortness of breath, and even cyanosis can occur when the lesion is extensive. Can be aggravated by infection, emphysema, bronchiectasis, pulmonary heart disease and so on. If the sarcoidosis affects other organs, the corresponding symptoms and signs may occur. For example, the most common skin is nodular erythema, which is more common in the face, neck, shoulders or limbs. There are also lupuspernio, lupus, pimples and so on. Subcutaneous nodules are sometimes found. Invasion of the scalp can cause hair loss. About 30% of patients have skin damage. About 15% of cases with impaired eyes may include iridocyclitis, acute uveitis, and corneal-conjunctivitis. Eye pain, blurred vision, ciliary body congestion and other manifestations may occur. Some patients have liver and/or splenomegaly, showing mild increase in bilirubin and elevated alkaline phosphatase, or liver damage. Mediastinal and superficial lymph nodes are often invaded and swollen. Such as involving joints, bones, muscles, etc., may have multiple arthritis, X-ray examination of the extremities of the limbs, small bones of the hand and foot of small cystic bone defects (bone cyst). Muscular granuloma can cause local swelling, pain, and the like. About 50% of cases involve the nervous system, and its symptoms vary. There may be clinical manifestations such as cranial nerve spasm, neuromuscular disease, intracerebral space-occupying lesions, and meningitis. When sarcoidosis affects the myocardium, there may be arrhythmia and even heart failure. About 5% of cases involve the heart. Pericardial effusion can also occur. Sarcoidosis can interfere with calcium metabolism, leading to increased blood calcium and urinary calcium, causing renal calcium deposits and kidney stones. Diabetes insipidus can be caused when the pituitary gland is involved. Excessive milk and elevated serum lactogen can occur when the hypothalamus is involved. When affected by parotid gland, tonsil, larynx, adrenal gland, pancreas, stomach, reproductive system, etc., it can cause related symptoms and signs, but it is rare. Sarcoidosis can involve an organ or multiple organs at the same time.

Pulmonary nodule examination

1.1 Laboratory inspection

Blood test: There may be leukopenia, anemia, and erythrocyte sedimentation rate during the progression of the activity. About 1/2 of the patients have elevated serum globulin, which is more common in IgG, followed by IgG and IgM. Plasma albumin is reduced. Increased blood calcium, increased serum uric acid, and increased serum alkaline phosphatase. Serum angiotensin-converting enzyme (SACE) activity increases in the acute phase (normal value is 17.6-34u/ml), which is useful for diagnosis. Serum interleukin-2-receptor (IL-2R) and soluble interleukin-2- The increase of receptor (sIL-2R) is of great significance for the diagnosis of sarcoidosis. It can also be elevated in a1-antitrypsin, lysozyme, ß2-microglobulin (ß2-MG), serum adenosine dehydrogenase (ADA), and fibronectin (Fn), which has certain reference significance in clinical practice.

Tuberculin test: About 2/3 of the nodule patients have no or very weak response to the skin test of 100 u tuberculin.

Sarcoidosis antigen (Kveim) test: 1:10 saline suspension was made into antigen in lymph nodes or spleen tissue of patients with acute nodules. Take 0.1~0.2ml of the suspension for intradermal injection. After 10 days, the purple pimples appeared at the injection site, and after 4-6 weeks, it spread to 3-8 mm, forming a granuloma, which was a positive reaction. The skin with positive reaction was removed for tissue diagnosis, and the positive rate was 75%-85%. There is a 2% to 5% false positive reaction. Because there is no standard antigen, the application is limited and has been gradually eliminated in recent years.

Biopsy: taking skin lesions, lymph nodes, anterior scale muscle fat pads, muscles and other tissues for pathological examination can help diagnose. Multiple biopsies taken at different sites can increase the positive rate of diagnosis.

Bronchoalveolar lavage fluid examination: Bronchoalveolar lavage fluid (BALF) in patients with sarcoidosis showed a significant increase in lymphocytes and polynuclear leukocytes in the alveolitis stage, mainly T lymphocytes, and the ratio of CD4+ and CD4+/CD8+ was significantly increased. In addition, the function of B cells is also significantly enhanced. The increase of IgG and IgA in BALF, especially the increase of IgG1 and IgG3 is more prominent. It has been reported that if the percentage of lymphocytes in the whole lung effector cells is greater than 28%, it indicates lesion activity.

Fiberoptic bronchoscopy lung biopsy (TBLB): The positive rate of TBLB in sarcoidosis can reach 63%~97%, the positive rate in stage 0 is very low, more than 50% in stage I can be positive, and the positive rate in stage II and III is higher.

X-ray examination: abnormal chest X-ray findings are often the primary finding of sarcoidosis, with more than 90% of patients with chest radiograph changes. At present, the regular X-ray film has not unified the staging of sarcoidosis. In 1961, Scandding divided the sarcoidosis into four phases (1 to 4), and in recent years it was divided into five phases (0, 1 to 4). At present, the more commonly used is the Siltzbach staging, and this classification method is also adopted in China.

Diagnosis of pulmonary nodules

Thoracic sarcoidosis: stage 0: no abnormal X-ray findings; stage I: hilar lymphadenopathy, no abnormalities in the lungs; stage IIA: diffuse lung lesions, hilar lymphadenopathy; stage IIB : diffuse lung lesions, without hilar lymphadenopathy; stage III: pulmonary fibrosis.

Multiple organ nodular disease in the whole body: both inside and outside the chest. (Extrapulmonary lymphadenopathy, eye or skin lesions are common, and nervous, digestive, cardiovascular, and endocrine systems can sometimes be affected).

Judging the activity of sarcoidosis: 1 Activity: progression of the disease, increased SACE activity, increased immunoglobulin or increased erythrocyte sedimentation rate. Bronchoalveolar lavage can be performed under conditions, according to the percentage of lymphocytes in the lavage fluid and the ratio of T helper cells/T suppressor cells, or 67 gallium scan to determine the activity; 2 no activity: SACE, immunoglobulin The objective indicators of T4/T8 are basically normal. The condition is stable.

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