Lipoma vs. cyst: how to spot the difference

What are lipomas and cysts?

A lipoma is a benign overgrowth of fat under the skin. Lipomas are usually quite soft and can occasionally cause pressure problems, but rarely get infected. Occasionally lipomas can become painful and may need to be removed.

Skin cysts (known as epidermoid cysts) are essentially an invagination of skin, that keep shedding the outer layers of skin within a closed capsule. This eventually gets bigger and bigger and can become infected and painful. Sebaceous cysts are rarer than skin cysts and more common in acne sufferers. The grease glands become blocked and the grease gradually fills up as a collection, which makes sebaceous cysts much harder to treat.

How can I tell the difference between a lipoma and a cyst?

At the early stages of a cyst and lipoma, they can feel quite similar. As cysts grow, they generally feel like an egg or rubber under the skin, they often have little drainage hole where white cheesy material can be seen discharging. Lipomas are usually a bit deeper in the skin and are usually soft and squeezy, and feel like they can be moved slightly under the skin.

Can both lipomas and cysts become cancerous?

Both are entirely benign and have a negligible risk of developing cancer, however occasionally these lumps are misdiagnosed and some rare cancers can present as a lump under the skin that may resemble a lipoma or cyst, so it is always best to get an expert medical opinion and see a specialist.

Can a lipoma and a cyst heal alone or do they need to be removed?

Lipomas rarely go away on their own but also rarely cause problems. I have plenty of patients who have not wanted to have their lipomas removed. Cysts can become infected and discharge completely. They can heal over with a scar but have a high chance of recurrence.

Small cysts are often easy to remove and will leave small scars. If you let your cyst grow and it becomes infected then it will be much harder to treat at a later stage and will have a higher chance of recurring. Therefore cysts are best removed early before they get infected. Both skin lesions are easily removed with surgery under local anaesthetic using simple procedures that leave small straight line scars.

When you notice a lump under your skin, it can be concerning. Two common causes of such lumps are lipomas and cysts. While both are generally harmless, understanding the differences can help you determine the next steps in addressing them.

What Is a Lipoma?

A lipoma is a benign tumor made up of fatty tissue. It is soft, movable, and typically painless unless it presses against nerves or grows near sensitive areas. Lipomas develop slowly and are usually found on the neck, shoulders, back, or arms. They are not cancerous and rarely require medical treatment unless they become bothersome.

Key Characteristics of a Lipoma:

• Soft and doughy to the touch
• Moves easily under the skin
• Typically painless
• Grows slowly over time

What Is a Cyst?

A cyst is a sac-like structure filled with fluid, air, or other substances. Cysts can form due to infections, blocked glands, or underlying conditions. Depending on the type, they may appear on various parts of the body. Some cysts may become red, swollen, or tender if they become infected.

Key Characteristics of a Cyst:

• Firm or soft, depending on the contents
• May appear red or inflamed if infected
• Can vary in size, sometimes growing quickly
• Often fixed in place

How to Tell the Difference

Here are some factors to help you differentiate between a lipoma and a cyst:

1. Texture and Movement
   Lipomas are soft and easily movable under the skin, while cysts are often firmer and may feel fixed in place.
2. Pain and Sensitivity
   Lipomas are usually painless, whereas cysts may cause discomfort, especially if they are infected or inflamed.
3. Appearance
   Cysts are more likely to have a visible head or opening, especially in the case of sebaceous cysts. Lipomas, on the other hand, appear as smooth, rounded lumps beneath the skin.
4. Rate of Growth
   Lipomas grow slowly over time, while cysts may grow more rapidly, particularly if they become infected.

When to Seek Medical Attention

Although both lipomas and cysts are typically harmless, you should consult a healthcare provider if:

• The lump grows quickly or changes shape
• It becomes painful or inflamed
• There is discharge or signs of infection
• You’re unsure about the nature of the lump

Treatment Options

Lipomas often don’t require treatment unless they cause discomfort or cosmetic concerns. In such cases, surgical removal is a common option.
Cysts may resolve on their own, but infected or bothersome cysts can be treated with drainage, medication, or surgical removal.

Final Thoughts

While lipomas and cysts share some similarities, their differences are usually evident upon closer examination. If you’re ever in doubt, it’s best to seek medical advice for an accurate diagnosis and appropriate care. Recognizing the signs early can provide peace of mind and ensure proper treatment if necessary.