Pathological examination of lung cancer

There are several ways to obtain lung cancer pathological diagnostic specimens:

1. Sputum cytology The results of sputum cytology depend on the following factors: ① The way of coughing. ② The location of the mass. ③ The size of the mass. ④ The histological type of the mass. ⑤ The experience of the cytopathologist.

There is a certain relationship between the number of specimens and accurate results. To obtain ideal results, sputum cytology examination requires at least 3 consecutive days of sputum specimens, while 4 days or more of sputum specimens cannot significantly increase the positive rate of the examination. The overall sensitivity of sputum cytology examination is about 82.8%. In areas with backward medical conditions, it is still a good detection method. However, false positive rates also occur from time to time, mainly due to viral infection and acute inflammation.

2. Fiberoptic bronchoscopy It has become a routine to perform fiberoptic bronchoscopy on patients with lung lesions. The fiberoptic bronchoscope can reach the level of the subsegmental bronchus. For most central lung cancers, not only can they be viewed directly under the microscope, but also a variety of cytological examinations can be performed, such as direct biopsy, fine needle aspiration biopsy through the bronchial wall, alveolar lavage, and biopsy under fluoroscope guidance. The sensitivity of biopsy is much more sensitive than alveolar lavage, especially for small cell carcinoma originating from the submembranous layer.

3. Ultrasound or CT-guided transthoracic fine needle aspiration biopsy is one of the more commonly used methods for obtaining histological examination materials. Whether the results of this examination are meaningful depends largely on the experience of the operator. However, due to various reasons, the accuracy of judging histological subtypes is only 75%. In clinical work, unless there is clear evidence of benign disease, malignant results should not be easily excluded.

4. Mediastinoscopy is currently the most accurate method for staging mediastinal lymph nodes. Indications for the use of mediastinoscopy include: ① Patients with lymph nodes larger than 1 cm on CT before thoracotomy. ② Candidates for neoadjuvant chemotherapy. ③ Patients with Tz or Ta stages with negative lymph nodes on CT, and patients with T1 adenocarcinoma or large cell carcinoma

5. Thoracoscopic examination is suitable for patients with lesions located in the outer 1/3 of the lung tissue and less than 3 cm, and pathological specimens can be obtained directly. Special attention should be paid to preventing iatrogenic spread during the operation.