For pathological diagnosis of lung cancer

The clinical symptoms and X-ray signs of lung diseases vary according to the location of the disease, the pathological type, and the early or late course of the disease, and are easily confused with other lung diseases. Therefore, the differential diagnosis of lung diseases, especially early cases, is of great significance for early diagnosis and early treatment.

1. Pulmonary tuberculosis

1. Pulmonary tuberculoma is easily confused with peripheral lung disease. Pulmonary tuberculoma is more common in young patients. The lesions are often located in the apex, posterior segment or dorsal segment of the upper lobe. Generally, the growth is not obvious, the course of the disease is long, and the density of the block shadow is uneven on the X-ray film. Sparse translucent areas can be seen, often with calcification points, smooth edges, clear boundaries, and there are often scattered tuberculosis lesions in the lungs.

2. The X-ray signs of miliary tuberculosis are similar to those of diffuse bronchioloalveolar disease. Miliary tuberculosis is common in young people, with obvious systemic toxic symptoms such as fever and night sweats. Anti-tuberculosis drug treatment can improve symptoms and the lesions will gradually absorb.

3. Hilar mass shadows of hilar lymph node tuberculosis on X-rays may be misdiagnosed as central lung disease. Hilar lymph node tuberculosis is common in young people, often with symptoms of tuberculosis infection, rarely with hemoptysis, and the tuberculin test is often positive. Anti-tuberculosis drug treatment has a good effect. It is worth mentioning that a small number of patients can have lung diseases and tuberculosis. Since there are no special clinical manifestations and X-ray signs are easily ignored, clinicians are often satisfied with the diagnosis of tuberculosis and ignore the coexisting disease lesions, which often delays the early diagnosis of lung disease. Therefore, for middle-aged and older patients with tuberculosis, if there are mass shadows in the site of tuberculosis lesions or other lung fields, the lung lesions have not improved after anti-tuberculosis drug treatment, the mass shadows have increased or are accompanied by atelectasis of lung segments or lobes, and the shadow of one side of the hilum has widened, it should arouse a high degree of suspicion of the coexistence of tuberculosis and lung disease, and further sputum cytology and bronchoscopy are necessary.

(ii) Pulmonary inflammation

1. Bronchopneumonia Obstructive pneumonia caused by early lung disease is easily misdiagnosed as bronchopneumonia. Bronchopneumonia generally has an acute onset, with obvious infection symptoms such as fever and chills. After antibacterial treatment, the symptoms disappear quickly and the lung lesions are absorbed quickly. If the inflammation is absorbed slowly or recurs, further in-depth examination should be conducted.

2. Lung abscess When the central part of the lung disease necrotizes and liquefies to form a diseased cavity, the X-ray signs are easily confused with lung abscess. Cases of lung abscess often have a history of aspiration pneumonia. In the acute phase, there are obvious symptoms of infection, with a large amount of sputum, purulent and smelly. On X-ray films, the cavity wall is thin, the inner wall is smooth, and there is a fluid level. The lung tissue or pleura around the abscess often have inflammatory lesions. During bronchography, the contrast agent can often enter the cavity, and is often accompanied by bronchiectasis.

3. Other chest diseases

1. Benign lung diseases Benign lung diseases sometimes need to be differentiated from peripheral lung diseases. Benign lung diseases generally do not present clinical symptoms, grow slowly, and have a long course. On X-ray films, they appear as nearly circular masses with calcification points, neat contours, clear boundaries, and usually no lobes.

2. Solitary metastatic disease in the lungs Solitary metastatic disease in the lungs is difficult to distinguish from primary peripheral lung disease. Differential diagnosis mainly relies on a detailed medical history and the symptoms and signs of the primary disease. Pulmonary metastatic disease generally presents less respiratory symptoms and blood in sputum, and it is difficult to find disease cells in sputum cytology.

3. Mediastinal disease Central lung disease may sometimes be confused with mediastinal disease. Diagnostic artificial pneumothorax helps to identify the location of the disease. Hemoptysis is less common in mediastinal disease, and sputum cytology fails to find disease cells. Bronchoscopy and bronchography help in differential diagnosis. Mediastinal lymphatic disease is more common in young patients, often with bilateral lesions, and may have systemic symptoms such as fever.

The clinical symptoms and X-ray signs of lung diseases vary according to the location of the disease, the pathological type, and the early or late course of the disease, and are easily confused with other lung diseases. Therefore, the differential diagnosis of lung diseases, especially early cases, is of great significance for early diagnosis and early treatment.

1. Pulmonary tuberculosis

1. Pulmonary tuberculoma is easily confused with peripheral lung disease. Pulmonary tuberculoma is more common in young patients. The lesions are often located in the apex, posterior segment or dorsal segment of the upper lobe. Generally, the growth is not obvious, the course of the disease is long, and the density of the block shadow is uneven on the X-ray film. Sparse translucent areas can be seen, often with calcification points, smooth edges, clear boundaries, and there are often scattered tuberculosis lesions in the lungs.

2. The X-ray signs of miliary tuberculosis are similar to those of diffuse bronchioloalveolar disease. Miliary tuberculosis is common in young people, with obvious systemic toxic symptoms such as fever and night sweats. Anti-tuberculosis drug treatment can improve symptoms and the lesions will gradually absorb.

3. Hilar mass shadows of hilar lymph node tuberculosis on X-rays may be misdiagnosed as central lung disease. Hilar lymph node tuberculosis is common in young people, often with symptoms of tuberculosis infection, rarely with hemoptysis, and the tuberculin test is often positive. Anti-tuberculosis drug treatment has a good effect. It is worth mentioning that a small number of patients can have lung diseases and tuberculosis. Since there are no special clinical manifestations and X-ray signs are easily ignored, clinicians are often satisfied with the diagnosis of tuberculosis and ignore the coexisting disease lesions, which often delays the early diagnosis of lung disease. Therefore, for middle-aged and older patients with tuberculosis, if there are mass shadows in the site of tuberculosis lesions or other lung fields, the lung lesions have not improved after anti-tuberculosis drug treatment, the mass shadows have increased or are accompanied by atelectasis of lung segments or lobes, and the shadow of one side of the hilum has widened, it should arouse a high degree of suspicion of the coexistence of tuberculosis and lung disease, and further sputum cytology and bronchoscopy are necessary.

(ii) Pulmonary inflammation

1. Bronchopneumonia Obstructive pneumonia caused by early lung disease is easily misdiagnosed as bronchopneumonia. Bronchopneumonia generally has an acute onset, with obvious infection symptoms such as fever and chills. After antibacterial treatment, the symptoms disappear quickly and the lung lesions are absorbed quickly. If the inflammation is absorbed slowly or recurs, further in-depth examination should be conducted.

2. Lung abscess When the central part of the lung disease necrotizes and liquefies to form a diseased cavity, the X-ray signs are easily confused with lung abscess. Cases of lung abscess often have a history of aspiration pneumonia. In the acute phase, there are obvious symptoms of infection, with a large amount of sputum, purulent and smelly. On X-ray films, the cavity wall is thin, the inner wall is smooth, and there is a fluid level. The lung tissue or pleura around the abscess often have inflammatory lesions. During bronchography, the contrast agent can often enter the cavity, and is often accompanied by bronchiectasis.

3. Other chest diseases

1. Benign lung diseases Benign lung diseases sometimes need to be differentiated from peripheral lung diseases. Benign lung diseases generally do not present clinical symptoms, grow slowly, and have a long course. On X-ray films, they appear as nearly circular masses with calcification points, neat contours, clear boundaries, and usually no lobes.

2. Solitary metastatic disease in the lungs Solitary metastatic disease in the lungs is difficult to distinguish from primary peripheral lung disease. Differential diagnosis mainly relies on a detailed medical history and the symptoms and signs of the primary disease. Pulmonary metastatic disease generally presents less respiratory symptoms and blood in sputum, and it is difficult to find disease cells in sputum cytology.

3. Mediastinal disease Central lung disease may sometimes be confused with mediastinal disease. Diagnostic artificial pneumothorax helps to identify the location of the disease. Hemoptysis is less common in mediastinal disease, and sputum cytology fails to find disease cells. Bronchoscopy and bronchography help in differential diagnosis. Mediastinal lymphatic disease is more common in young patients, often with bilateral lesions, and may have systemic symptoms such as fever.