What are the Differences Between a Cyst and a Lipoma?

If you’ve noticed a lump under your skin, it’s natural to be concerned. While many people immediately think of tumors or cancer, most skin lumps turn out to be harmless—typically either a cyst or a lipoma. So, what’s the difference between the two? And when should you see a doctor?

Let’s break it down.

What Is a Lipoma?

A lipoma is a slow-growing, fatty lump that forms between your skin and the underlying muscle. These soft, doughy lumps are typically:

• Noncancerous
• Movable when pressed
• Painless, though they can become tender if pressing on nearby nerves

Most lipomas are small—less than 2 inches in diameter—and commonly appear on the shoulders, back, thighs, or arms. They tend to occur more often in adults between the ages of 40 and 60, and they sometimes run in families.

What Causes a Lipoma?

The exact cause of lipomas isn’t fully understood, but they’re thought to be related to:

• Genetics (family history of lipomas)
• Minor injuries or trauma
• Certain inherited conditions such as Dercum’s disease or Gardner syndrome

While lipomas are benign and usually harmless, they can sometimes grow large or painful enough to warrant removal.

What Is a Cyst?

A cyst is a closed sac-like structure filled with fluid, pus, or other material. They can form anywhere on the body, including the skin, scalp, or internal organs.

Cysts are typically:

• Round and firm to the touch
• Located just beneath the skin
• Painless, unless infected or inflamed

Common types of cysts include sebaceous cysts, epidermoid cysts, and pilar cysts.

What Causes a Cyst?

Cysts can form for many reasons, including:

• Blocked glands or hair follicles
• Infections
• Ingrown hairs
• Chronic skin conditions like acne

Cysts may become red or swollen if infected and can rupture or drain. While generally harmless, cysts can be uncomfortable or unsightly—leading many patients to seek removal.

How to Tell the Difference Between a Cyst and a Lipoma

When Should You See a Doctor?

Even though both lipomas and cysts are usually benign, it’s important to have any new or changing lump examined by a healthcare provider. You should schedule an appointment if:

• The lump is growing rapidly
• You experience pain or discomfort
• The lump becomes red, hot, or drains fluid
• You have a personal or family history of cancer

What Are Your Treatment Options?

Treatment isn’t always necessary for lipomas or cysts unless they’re causing pain, infection, or cosmetic concern. However, removal options include:

• Surgical excision – Complete removal of the lump under local anesthesia
• Steroid injections – To shrink or reduce inflammation
• Antibiotics – If the cyst becomes infected

BASS Medical Group: Your First Step in Getting Checked

At BASS Medical Group, our experienced Primary Care Providers (PCPs) are here to evaluate any concerning lumps or skin growths. While we do not have in-house dermatologists, your PCP can:

• Examine the lump
• Prescribe antibiotics or treatment if needed
• Refer you to a specialist or surgeon for removal or biopsy if necessary

Early evaluation can offer peace of mind—and potentially prevent more serious complications.

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