Tumors fall into two categories: benign and malignant. Malignant tumors are tumors that are cancerous and can cause death or other serious problems. Benign tumors are simply growths that do not spread beyond their borders. Benign and malignant tumors both can grow anywhere in the body. The two types of tumors share many characteristics, but there are some signs that a tumor is probably benign. There are exceptions to tumor symptoms, but for the most part, benign tumors behave in a very specific way that differentiates them from their malignant counterparts.
Benign tumors have very clearly defined borders and are well-contained, meaning they do not invade the tissues near them. Malignant tumors invade surrounding tissues. When feeling the tumor, smooth edges indicate well-defined borders. Rough edges indicate poorly-defined borders.
Benign tumors stay in one place. Malignant tumors spread, either to surrounding tissues or to other areas of the body via lymph nodes.
A slow-growing tumor is most often benign. Those that grow rapidly are at high risk for malignancy. If a tumor is visible from the outside, growth is easy to gauge by simple measurement. If it is internal, measurement by some form of imaging is the only way to tell if it is growing. Any tumor that suddenly appears is most likely fast-growing, and therefore the likelihood of it being benign is lower.
If a benign tumor is palpable, its well-defined margins and containment make it fairly easy to move around. A malignant tumor sticks to what it invades, making it very difficult to move around.
While computerized tomography (CT) and magnetic resonance imaging (MRI) are helpful in locating and analyzing the appearance of a tumor, they cannot determine whether a tumor is malignant or benign. The only way to evaluate a tumor for malignancy is by biopsy.
Tumors presenting with pain are no more likely to be malignant than any other tumor. Benign tumors growing in contained areas may cause significant pain and problems. Brain tumors, gastrointestinal tumors and nerve tumors, even when benign, cause serious pain and organ dysfunction. Some malignant tumors may cause no pain or discomfort whatsoever.
Any suspected tumor, large or small, warrants a trip to a doctor. Many times, doctors recommend biopsies to ensure that the growth is benign. Malignant tumors may have all the signs of a benign tumor, and if left untreated can cause death. It is imperative to biopsy any growth to eliminate the possibility of malignancy.