Pathological histological diagnosis is the only basis to determine the diagnosis. Currently, only for primary hepatocellular carcinoma, the diagnosis can be determined based on methemoglobin and the corresponding imaging diagnosis, with the exclusion of pregnancy, chronic active hepatitis and other diseases, except for all cancer patients, the diagnosis must be finalized based on pathological histological diagnosis. There are various methods to obtain the lesion tissue: surgery, puncture, endoscopy, clamping and brushing of exposable tissues and organs, and scraping for endometrial cancer. Each method has its indications and contraindications, and different suspected patients have different clinical characteristics. For example, patients with lung cancer are often considered for fiberoptic bronchoscopic biopsy by forceps or brush, but when the patient is combined with hemoptysis, severe respiratory dysfunction, severe myocardial ischemia or new heart attack, it is a contraindication, or if the lesion is peripheral lung cancer and does not involve the segmental bronchial opening Patients with peripheral lung cancer that does not involve the segmental bronchial opening should not be used because the mirror cannot be reached, and puncture for tissue biopsy should be considered. Another example is surgical excisional biopsy of subcutaneous masses, in which complete excisional biopsy should be considered and partial excisional biopsy should be avoided as much as possible. Puncture biopsy is widely accepted in clinical diagnosis of tumors, but it should be selected according to the characteristics of the patient’s condition before puncture, for example, if the lesion is small and adjacent to large blood vessels, it should not be used. For example, if the lesion is small and adjacent to large blood vessels, it should not be used. If the patient’s special condition makes it impossible to obtain pathological diagnosis through biopsy, the diagnosis can be clarified by finding cancer cells shed from pleural fluid, ascites, pericardial effusion and sputum. After obtaining histopathological or cytological diagnosis, relevant comprehensive examinations should be done to clarify the situation around the primary lesion and whether there is distant metastasis, etc., to clarify the disease stage and provide a basis for the next clinical treatment.