Mammograms can help screen for benign or malignant neoplasms of the breast.
Neoplasms are abnormal tissue growths or masses in the human body. The word "neoplasm" is synonymous with "tumor" and the two are often used interchangeably. Neoplasms can be divided into two classes: benign neoplasms, which are seldom life-threatening, and malignant neoplasms or cancerous tumors, which may be life-threatening and exhibit a variety of characteristic features.
Benign Tumors
Unlike a malignant tumor, a benign tumor does not spread to other parts of the body. It may grow or expand slowly and push aside the tissue around it, but it does not invade surrounding tissue, and it's often encapsulated. The cells inside it still closely resemble the cells in their tissue of origin. They can usually be removed if desired and in most cases do not come back following surgery.
Malignant Tumors
Malignant tumors, by contrast, can represent a serious threat to the patient's long-term health. Unlike benign tumors, they grow in all directions and infiltrate neighboring tissues, they are seldom encapsulated and they have lost most if not nearly all resemblance to the cells in the tissue of origin. When removed by surgery, they can recur if the tumor has invaded the surrounding tissue, so that some of the tumor cells escaped the surgeon's knife. Finally, tumors can often spread via the bloodstream to other sites in the body, a process called metastasis.
Cell Cycle
The rate at which cells in your body divide is closely controlled both by processes inside the cell and signals secreted by other cells. Cancer cells in malignant tumors defy or ignore these signals and continue to divide even when external signals are absent. Crucially, they are less likely than normal cells to commit suicide in response to DNA damage. Cells in benign tumors also divide more often than they should, but they lack a cancer cell's ability to invade and/or metastasize.
Angiogenesis & Immortality
Normal cells can only divide a set number of times. If you grow human cells in tissue culture, they will cease to divide after a set number of rounds of replication. Cancer cells, by contrast, are immortalized and will continue to divide indefinitely. They are also able to recruit new blood vessels to increase the blood supply to the malignant tumor. Benign tumors do not typicaly display these dangerous, aggressive features.
Tags: benign tumors, Cancer cells, cells tissue, continue divide, malignant neoplasms, malignant tumor
