Cancerous tumors can be grouped into two types malignant and benign. Benign Tumors stopped growing and looked much like normal organ cells when seen under microscope. Malignant tumors in contrast grew relentlessly and led to skin ulceration and debilitation. Malignant tumors bore less resemblance to normal cells and always had a frenzied look when looked under microscope.
Fortunately most tumors are merely lazy lumps of slow growing cells. Though benign ones may look like neighboring cells they do little or no work. This growth can be life threatening too but in a different sense. For purely mechanical reasons these tumors can turn fatal. For example a growth in brain can squeeze healthy cells and cause pressure build up inside the rigid and non expandable skull. Benign tumors called myxoma are also common in heart they can grow in size and choke the blood flow to heart. Such benign growth called uterine fibroids is common in the uterus of women. Most of the time it causes no problem but if it grows in size it then may it may cause sever pain and bleeding requiring hysterectomy.
Benign tumors are known for bad things that they do not do unlike their malignant cousins. They do not grow fast without limit. They do not destroy the active neighboring cells nor are they metastatic to other organs. These tumors stop growing on their own and sometimes disappear spontaneously. But it does cause fear and horror when it first appears. These tumors are covered by an outer surface that prevents them from behaving in a malignant manner. However many types of them have the potential to become malignant. One of the most common benign growths that can turn malignant is tubular adenoma. It is a polyp in colon that is often considered as a precursor to cancer. Otherwise most benign tumors do not need any treatment at all. However if they cause any health risk to the patient then surgery is the only way to treat them as they do not respond to radiation or chemotherapy.