A secondary tumor is what is called a metastatic tumor, one that has metastasized from somewhere else, and usually the tumor didn’t grow in this area in the first place. Primary tumors are those in which this tumor is growing in this area. Secondary malignant tumors, also known as metastatic malignant tumors, are usually malignant tumors of organs and tissues. It is usually not a primary tumor of that organ and tissue, but a malignant tumor that has metastasized from other organs and tissues. For example, breast cancer is a primary malignant tumor in the breast tissue, but when breast cancer metastasizes to the brain, this brain malignancy may be called a secondary malignant tumor. Primary tumors are tumors that first appear in a specific area, such as the lungs, liver, intestines, head, or skin. They may be called primary lung cancer, primary liver cancer, primary colon cancer, etc. It is suggested that patients should go to regular hospitals to clarify the cause and symptomatic treatment in time after the appearance of the disease, so as to avoid delaying the condition and causing adverse consequences.