What is a Neoplasm?

Not all neoplasms are cancerous.

breast cancer cells
Breast cancer cells. STEVE GSCHMEISSNER/Science Photo Library/Getty Images

A neoplasm is an abnormal clump of cells in the body. While the medical term neoplasm is often used in relation to cancer, it can also refer to benign or non-cancerous health conditions. Neoplastic cells simply refers to the cells that make up that neoplasm or clump of cells. 

How Does a Neoplasm Form?

In the human body, there are trillions of normal, healthy cells. These cells grow, divide, and die in a controlled manner.

But in the case of a neoplasm, the cells that make up the neoplasm do not behave and are not controlled like normal cells. Instead, these cells live longer and divide faster, and they will continue to divide and grow if not treated.

Are all Neoplasms Cancerous?

No. Neoplasms can be cancerous—also termed malignant—or they can be non-cancerous, called benign. While benign tumors can grow large and crowd upon a person's healthy organs, they are generally not life-threatening and are usually curable. They also cannot grow into and replace healthy tissue in our body, like a malignant tumor can. In other words, benign neoplasms stay within their area, meaning they do not spread to more distant parts of the body through the bloodstream or lymph nodes—this process is called metastasis.

An example of a malignant neoplasm is breast cancer, which is an an abnormal growth of cells that originates within the breast and can spread throughout the body if not treated.


An example of a benign neoplasm is a fibroid in the uterus, which may cause vaginal bleeding or pelvic discomfort, but is not cancerous and will not spread throughout the body if left untreated.

In other words, while a person will eventually die of breast cancer if left untreated, a fibroid is not considered deadly.

That being said, fibroids can cause significant bleeding (rarely, this is life threatening) or pain, and so sometimes need to be removed.

The big picture here is that not all neoplasms are cancerous. Another important point here is that while tumors are often used interchangeably with the term neoplasm, not all neoplasms are tumors. One classic example is leukemia, which is a cancer of the blood that does not form a distinct mass. 

Why Do Malignant Neoplasms Form?

Cells contain genetic material called DNA and when the DNA of a cell is damaged, a healthy cell repairs it or dies. Cancer cells, on the other hand, do not repair the DNA or die. Instead, they continue to grow and divide, making more cells containing that bad DNA. 

DNA can become damaged spontaneously without a known cause, or by a known cause like sun exposure, tobacco, radiation, or certain chemicals. 

What Type of Doctor Do I See if I Have a Malignant Neoplasm?

If your doctor is suspicious for a malignant neoplasm (which means cancer), or you have been diagnosed with one through a tissue biopsy, you will be referred to a doctor who specializes in cancer called an oncologist. Depending on the type and stage of cancer, you may be treated with surgery, chemotherapy, and/or radiation.


American Cancer Society. (December 2015). What is Cancer? 

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