Abnormal growth is a term used to describe any type of growth that is not normal or expected. This can include tumors and cysts. A TUMOR is an abnormal mass of tissue that can be benign or malignant, while a CYST is a closed sac-like structure that can contain fluid, air, or other substances. Both tumors and cysts can cause abnormal growth in the body and can be caused by a variety of factors, including genetics, environmental factors, and lifestyle choices.