What is the difference between a cyst and a tumor?

For most of us, it is not easy to tell the difference between a cyst and a tumor. In both cases, it is a lump that appears somewhere in the body and that, usually, generates alarm, because it is immediately associated with a cancerous process.

The belief that the difference between a cyst and a tumor is very common is that the former is benign and harmless, while the latter is malignant and fatal. That's not true. There are cysts that can be dangerous and there are also tumors without consequences.

An important difference between a cyst and a tumor is the cause that causes them. Also, of course, its composition and its course. Although both are sometimes very similar in appearance, the truth is that they have a different nature and implications.

The cysts

Cysts are bags or sacs that contain a gaseous, liquid or semi-solid material, which is surrounded by a membrane. Most often they appear spontaneously and often disappear in the same way. Usually, they are formed by the obstruction or infection of some gland.

There are different types of cysts. The most common are the following:

  • Breast cysts: These are bags filled with fluid that appear in the breasts and move easily under the skin. If the cysts in the same breast are many, then there is talk of mammary fibrocystic disease.
  • Follicular cysts: These are bags that form in the hair follicles and that generally contain keratin. They almost always form in the scalp.
  • Epidermoid cysts: are the cysts that form in the epidermis, basically in the chest, back, neck and scrotum.
  • Ovarian cysts: they form in the ovaries, usually during ovulation. Sometimes, they can cause pain and discomfort.
  • Liver cysts: they form in the liver.
  • Renal cysts: are located in the kidneys.

The cysts have different sizes. Sometimes, they are no bigger than the tip of a pin and, other times, they get to be the size of a basketball. The most dangerous are the largest, because of the potential damage they can cause to nearby organs.


Tumors are bulges that arise from the division and uncontrolled growth of some cells.. These accumulate and form those lumps or lumps, which become tumors, also called neoplasms.

Tumors may be the result of some disease., problems related to the immune system, alcohol or tobacco consumption, prolonged exposure to the sun, contact with certain toxins or chemicals, radiation, obesity, viruses and other factors.

You may be interested: Can head lumps be tumors?

The tumors can be benign, premalignant or malignant; that is, non-cancerous, precancerous or cancerous, respectively. The main types of tumors are the following:

  • Lipomas: are tumors that form with fat cells, are located under the skin and are soft. They are almost always benign and generally appear in people over 40 years old.
  • Fibroids: they form in the fibrous or connective tissues, very frequently on or around the uterus. They are benign tumors.
  • Adenomas: they form in the layer that covers the organs and glands. They are composed of glandular epithelial tissue. Generally, they are benign.
  • Malignant: can be formed in any part of the body. They are cancerous tumors.

Read also: Malignant and benign tumor, what are the differences?

Difference between a cyst and a tumor

As you can see, the difference between a cyst and a tumor is given by several factors. The first one is the cause. While cysts are usually formed by obstruction or infection in a gland, tumors are the result of excessive growth of a group of cells.

Likewise, While cysts generally contain air, fluid, or a semi-solid substance, tumors are solid masses of tissue.. Almost all cysts are benign, but cancer also results in the appearance of a significant number of cysts. Cysts that contain solid material can be cancerous.

Another important difference between a cyst and a tumor is that the former usually have mobility. That is, they can move from one place to another just by touching them. Tumors, on the other hand, present themselves as a rigid mass, which is firm and cannot move; It seems as if it is ‘seized’ to the body

Both cysts and tumors can appear anywhere in the body and require a medical evaluation. The danger of one or the other depends on several factors and, therefore, it is necessary to carry out the case tests to establish a diagnosis.