Cyst vs. Lipoma: What Are the Differences?

Cysts and lipomas are two types of lumps that can be found under the skin. Cysts are enclosed sacs filled with fluid, pus, air, or other substances. Cysts are benign, meaning not cancerous.

Lipomas are growths of fatty tissue usually found between the muscle and skin. Like cysts, lipomas are also benign.

Cysts and lipomas can look and feel very similar but are very different types of growths. It can be difficult to tell them apart. This article will highlight the differences between cysts and lipomas.

Symptoms

A cyst and lipoma are both lumps that can be found underneath the skin and other places in the body. They are generally small and painless. But these two types of lumps are very different.

Symptoms of a Cyst

The symptoms of a cyst will vary greatly based on its location and type. Here are the most common cyst symptoms:

• Firm lump
• Swelling around the cyst
• Tender to the touch
• Redness
• Pain, especially if the cyst ruptures

Cysts can be asymptomatic (cause no symptoms). This is especially true if they are found inside the body, near organs. When cysts cause symptoms, the symptoms will be reflective of the cyst's location. For example, a cyst found in the wrist can cause decreased grip strength.

Symptoms of a Lipoma

A lipoma, sometimes called a fatty tumor, is a collection of fat cells that form a lump under the skin. Lipoma symptoms and characteristics will vary from person to person, but the most common are:

• A soft, doughy lump
• A lump that moves easily when pressed
• A painless lump, unless pressing against nerves or if it contains blood vessels
• A small lump (usually 2inches in diameter)

Besides the lump, a lipoma near the skin is usually asymptomatic. However, when they grow inside the body, lipomas can cause symptoms that are specific to their location. Examples are a lipoma growing in the airway that will cause difficulty breathing or a lipoma growing in the heart that can cause an irregular heartbeat.

Causes

Cysts and lipomas have different causes.

Cyst Causes

In general, a cyst is caused when a fluid or substance is trapped in a space and creates an enclosed capsule. There are several types of cysts. Each type has its own cause. Below are some types of cysts and their causes:

• Sebaceous cyst: Caused by trapped secretions from certain glands
• Ganglion cyst: Caused by a minor injury that starts when there is a collection of joint fluid in a sac structure
• Ovarian cyst: Can be caused when an ovarian follicle doesn't release its egg

Lipoma Causes

Experts are not sure what causes a lipoma. There are studies that show a genetic factor in their development. Another theory is that an injury can cause a lipoma to form.

Risk factors for developing a lipoma include:

• Problems with weight control and obesity
• Liver disease
• Alcohol misuse
• Glucose intolerance (a group of conditions resulting from high glucose levels)
  

Diagnosis

In most cases, a healthcare provider can diagnose a cyst or lipoma by looking at and touching it. They will examine its shape, size, and determine if there are any signs of infection or swelling. That typically is enough for a healthcare provider to determine if the bump is a cyst or lipoma. However, a healthcare provider may order additional testing. This can include:

• Biopsy: A biopsy(surgical removal of tissue to be analyzed in a lab) is done to determine if the lump has cancerous cells. It is more common for a lipoma to be examined for cancerous cells after it has been fully removed.
• Diagnostic imaging: An ultrasound, computed tomography (CT), or magnetic resonance imaging (MRI) can help healthcare providers understand the size, how deep it goes into the tissue, and look for other abnormal growth.
  

Treatment

Treatment isn't necessary for most lipomas and cysts. They can be watched and if they start to grow, cause pain, or show signs of infection they may be removed. Here are the specific treatments for a lipoma and cyst:

Cyst Treatment

There are several kinds of cysts, and treatment will be different for each kind. If a healthcare provider determines that the cyst is not causing problems, then no treatment is necessary. But if the cyst is painful or poses a health risk, they may be treated with fluid removal or surgical removal.

Fluid removal uses a needle to withdraw fluid from the cyst. The problem with this treatment is that the cyst can refill and continue to cause problems. Surgical removal removes the whole cyst, the fluid, and the outer encasing. This decreases the likelihood the cyst will grow back.

Lipoma Treatment

Most times, a lipoma does not need treatment. It tends to be more of a cosmetic concern than a health concern. However, if the patient or healthcare provider would prefer it be removed, then it usually will be surgically removed.

In this procedure, a small incision is made to allow the full removal of the fatty tumor. This is best done when the lipoma is small to prevent intruding on nerves, blood vessels, or joints.

Prevention

There is no way to prevent most lipomas or cysts. Understanding the differences between the two can help people identify the lump and get a quick diagnosis and prompt treatment.

Summary

Cysts and lipomas are two common lumps that people may find on their bodies. While they may look similar at first, these lumps have many differences. A cyst is a sac filled will fluid, pus, air, or other substances. A lipoma is a lump of fatty tissue and is sometimes called a fatty tumor.

A healthcare provider can usually diagnose these lumps based on their appearance. Occasionally, additional testing is necessary. Treatment isn't necessary unless the lump is causing other health problems.

A Word From Verywell

Finding a lump under your skin can be unnerving. Contact your healthcare provider for a diagnosis and treatment plan. Many people who have a cyst or lipoma do not need treatment. But if the lump hurts, is swollen, is getting bigger, or is just something you'd like to have gone then surgical removal is the best option to prevent it from coming back.