What is the main basis for diagnosing malignant tumors

The main basis for diagnosis of malignant tumors is pathological examination, cytological examination, imaging examination, detection of tumor markers, etc. 1. Pathological examination is the gold standard for diagnosis. Pathological examination observes the microstructure of tissue samples through microscopy to identify malignant features such as atypical, abnormal proliferation and invasive growth of cells. This process directly determines the final judgment of tumor nature. 2. Cytological examination is performed by obtaining cells from body fluids or tissue samples of patients, staining and microscopic examination. Observing changes in cell morphology, size, nucleus-cytoplasm ratio, etc. If malignant cell characteristics are found, such as enlarged nuclei and irregular morphology, it is of great significance for the diagnosis of malignant tumors. 3. Imaging examinations such as CT, MRI, PET-CT, etc., although these examinations cannot directly diagnose malignant tumors, they can provide important information such as tumor location, size, morphology and relationship with surrounding tissues, which provides basis for clinical diagnosis and treatment plan formulation. 4. Tumor marker detection detects the level of specific tumor-associated antigens or proteins in the blood as an auxiliary diagnostic tool for malignant tumors. Although its specificity and sensitivity are limited, it still has important value in some tumor types.