Is phyllodes tumor killing you slowly?

There is no evidence to suggest that phyllodes tumors are typically fatal. However, phyllodes tumors can be locally aggressive and grow rapidly. If left untreated, phyllodes tumors can cause significant damage to the breast tissue and surrounding structures, including the skin, muscles, and chest wall. Rarely, phyllodes tumors can spread to other parts of the body, such as the lungs or bones.