Ca is the abbreviation of the English word Cancer, which translates to mean cancer in Chinese. In medical science, cancer is defined as malignant tumors originating from epithelial tissues collectively called cancer, which is a common malignant tumor, malignant tumors originating from mesenchymal tissues collectively called sarcoma, and cancer referred to in daily life is collectively referred to all malignant tumors. Malignant tumors have several characteristics such as uncontrolled growth, aggressiveness and metastasis. The occurrence of malignant tumor is a complex process involving multiple factors and steps, including triggering factors, cancer-promoting factors, evolutionary process and generation of cancer. The final diagnosis of malignant tumor is needed to be clarified by the histopathological diagnosis. The diagnosis of histopathology is obtained by puncture biopsy, excisional biopsy or resection biopsy.