What tests can help differentiate between lung cancer and tuberculosis

For patients with lung diseases, if a lung mass is found during clinical examination, it is often necessary to differentiate between lung cancer and tuberculosis. The clinical manifestations of the two are similar, and both may have symptoms such as cough, hemoptysis, chest tightness, chest pain, fever, appetite and weight loss, which are difficult to distinguish based on symptoms alone. Therefore, some examination items are needed to distinguish between lung cancer and tuberculosis in clinical practice.

Sputum etiology examination: It is an important examination item for distinguishing lung cancer from pulmonary tuberculosis. Acid-fast bacilli can often be found in multiple 24-hour sputum concentration examinations of pulmonary tuberculosis patients; and cancer cells can often be found in the fresh sputum coughed up by lung cancer patients.

Chest X-ray: Chest X-ray and lesion tomography are helpful in differentiating lung cancer from tuberculosis. Patients who meet the conditions can also undergo chest CT examination.

Fiberoptic bronchoscopy: It is also helpful in distinguishing the two.

Lung tissue biopsy: Fiberoptic bronchoscopic lung biopsy or percutaneous lung biopsy can help differentiate the two, but the examination is invasive and should be considered carefully.

When diagnosis is difficult, experimental anti-tuberculosis treatment for 2 to 4 weeks can be performed, and chest X-rays can be taken before and after treatment for comparison, which can often provide diagnostic clues and link the patient's clinical symptom changes, which is helpful for early diagnosis and screening of the disease. In addition, tuberculin tests, serum carcinoembryonic antigen, erythrocyte sedimentation rate, C-reactive protein and other related tests can also be performed. If identification is still difficult and surgical conditions are available, thoracotomy can be considered.