Differences Between Benign and Malignant Tumors. By MUHAMMAD BILAL ASHRAF GONDAL. 1-Rate of growth - In general, malignant tumors grow much more rapidly than benign tumors, but there are exceptions. Some malignant (cancerous) tumors grow very slowly, while some benign tumors grow rapidly. 2-Ability to metastasize - Benign tumors expand locally, whereas malignant tumors can spread (metastasize) to other parts of the body by way of the bloodstream and lymphatic channels. Check this article to see how cancer spreads. 3-Site of recurrence - While benign tumors may recur locally — that is, near the site of the original tumor — malignant tumors may recur at distant sites, such as the the brain, lungs, bones and liver, depending on the type of cancer. 4-”Stickiness - The cells in benign tumors manufacture chemicals (adhesion molecules) that cause them to stick together. Malignant tumor cells do not produce these molecules and can break off and “float away” to other regions of the body. 5-Tissue invasion - In general, malignant tumors tend to invade nearby tissues, whereas benign tumors do not (though they may grow large and cause damage to nearby organs by creating pressure on them). A very simplistic way of thinking about this is to envision a benign tumor as having a wall or boundary (literally, a fibrous sheath surrounding the tumor). This boundary allows the tumor to expand and push (displace) nearby tissues aside, but does not allow the tumor to penetrate nearby tissues. In contrast, envision cancer as having “fingers” or “tentacles” that can reach into nearby tissues. In fact, the Latin word cancer derives from the word crab, used to describe the crablike, or fingerlike, projections of cancerous tumors. 6-Cellular appearance - Under a microscope, cells that are benign often look much different from those that are malignant. One of these differences is that the cell nucleus of cancer cells is often larger and appears darker due to an abundance of DNA. 7-Effective treatments - Benign tumors can usually be removed with surgery alone, while cancerous (malignant) tumors will often require chemotherapy and radiation therapy. These additional treatments are needed to attempt to reach cancer cells that have spread beyond the region of the tumor or are left behind after surgery for a tumor. 8-Likelihood of recurrence - Benign tumors seldom recur after surgery, whereas malignant tumors recur much more commonly. Surgery to remove a malignant tumor is more difficult than surgery for a benign tumor. Using the fingerlike analogy above, it is much easier to remove a tumor that has a clear fibrous boundary than a tumor that has penetrated nearby tissues with these fingerlike projections. If cells are left over from these fingers, the tumor is more likely to come back. 9-Systemic effects - Malignant tumors are more likely to have systemic, or total body, effects than benign tumors. Due to the nature of these tumors, symptoms such as fatigue and weight loss are common. Several types of malignant tumors also secrete substances that cause effects on the body beyond those caused by the original tumor. An example of this is the paraneoplastic syndrome caused by some cancers, resulting in a wide array of physical symptoms from hypercalcemia (an elevation of calcium in the blood) to Cushing’s syndrome (which in turn causes symptoms such as rounding of the face, stretch marks and weakened bones). 10-Death toll - Benign tumors cause around 13,000 deaths per year in the United States. The number of deaths that can be blamed on malignant (cancerous) tumors is over 575,000.
Posted on: Sat, 13 Sep 2014 09:34:27 +0000
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