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 get infected and painful. Sebaceous cysts are rarer that skin cysts and more common in acne sufferers, the grease glands become blocked and the grease gradually fills up as a collection – these are 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 they 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 with simple procedures leaving small straight line scars.