Cysts are not cancer; cysts are a benign condition while cancer is a malignant tumor. Cysts have almost no effect on the whole body, and only when they are large do they show symptoms of localized pressure and obstruction. Cancer is a rapidly growing, immaturely differentiated, metastatic and invasive malignant tumor with serious systemic effects. Generally, cysts grow slowly and show gradual enlargement. In contrast, tumors grow rapidly and have a shorter course. Clinically, the treatment of cysts is relatively simple. Some cysts require only radical surgery and no adjuvant radiotherapy or chemotherapy after surgery. The treatment effect is good and the recurrence rate is low. For the treatment of malignant tumors, there are a variety of therapeutic measures, but the therapeutic effect is not ideal. Once metastasis and recurrence occur, it usually jeopardizes the patient’s life. For the differential diagnosis of cysts, it is necessary to combine the history and auxiliary examination. Simple cysts and cancer can be accurately identified by color Doppler ultrasound, CT or MRI. After diagnosis, you need to cooperate with doctors to actively carry out treatment and recover as soon as possible.