A cyst is a fluid or debris-filled sac that forms just under the skin, while a lipoma is a soft, slow-growing lump made of fatty tissue that develops slightly deeper. Both are almost always benign, but they form differently, feel different to the touch, and are removed using different techniques, which is why an accurate diagnosis from a dermatologist matters more than the lump’s size or appearance alone.
Because both conditions can appear as a painless bump under the skin, patients often assume they are the same thing until a professional exam sorts out the difference.
What Is a Cyst?
A cyst forms when skin cells or fluid become trapped beneath the surface, creating a closed sac that can slowly fill and grow over time. The most common type seen in dermatology, an epidermoid cyst, often has a small central pore visible on the skin and can occasionally become inflamed, tender, or infected, particularly if squeezed or irritated.
Cysts tend to feel firm but slightly movable under the skin, and they can appear anywhere on the body, though the face, neck, and back are especially common locations.
What Is a Lipoma?
A lipoma is a benign growth composed of fat cells that develops in the layer of tissue just beneath the skin. Unlike a cyst, a lipoma has no central pore and is not prone to infection, since it is not connected to the skin’s surface in the same way.
Lipomas tend to feel soft and doughy, move easily under light pressure, and grow very slowly, often over months or years, without causing pain unless they press on a nearby nerve.
How Can You Tell Them Apart Without an Exam?
Texture and mobility are the two most noticeable differences at home, though neither should replace a professional evaluation. A cyst typically feels firmer and may have a visible central pore, while a lipoma feels softer and moves more freely under the fingers. Cysts are also more likely to become red, tender, or swollen if irritated, while lipomas rarely change in appearance beyond gradual, slow growth.
Because several types of benign and, less commonly, more serious growths can mimic either presentation, a physical exam remains the only reliable way to confirm which one is present.
When Should a Cyst or Lipoma Be Removed?
Removal is not always medically necessary, since both are typically benign and can be left alone if they are not causing discomfort or cosmetic concern. Cysts are more often removed when they become recurrently inflamed, infected, or bothersome, while lipomas are typically removed when they grow large enough to be uncomfortable, restrict movement, or affect appearance.
Removal for either condition is generally a straightforward, in-office procedure, and the tissue removed can also be evaluated afterward to confirm the diagnosis.
Is a Cyst or Lipoma Ever a Sign of Something More Serious?
The overwhelming majority of cysts and lipomas are benign and not a cause for concern. That said, any new lump that grows quickly, feels unusually hard or fixed to surrounding tissue, or is accompanied by pain, should be evaluated by a dermatologist promptly rather than assumed to be a routine cyst or lipoma. A professional exam is the only way to rule out a less common but more serious cause.
Frequently Asked Questions
Are cysts and lipomas painful? Most cysts and lipomas are painless. Cysts can become tender if they become inflamed or infected, while lipomas are typically only uncomfortable if they grow large enough to press on a nerve or muscle.
Can a cyst or lipoma go away on its own? Cysts occasionally drain or shrink on their own but often refill and recur, while lipomas do not typically go away without removal, since they consist of stable fatty tissue rather than fluid.
Is removal of a cyst or lipoma covered by insurance? Coverage depends on the individual insurance plan and whether removal is considered medically necessary versus cosmetic. This is best confirmed directly with your insurance provider and the practice before scheduling.
Does removing a cyst or lipoma leave a scar? Any removal procedure that involves an incision will leave some scarring, though the size and visibility depend on the size and location of the growth and the technique used.
How fast do lipomas typically grow? Lipomas typically grow very slowly over months or years. Rapid growth is unusual for a lipoma and warrants prompt evaluation.
Conclusion
Cysts and lipomas can look similar at a glance, but they form differently, feel different to the touch, and are treated differently, which is why a dermatologist’s exam is the most reliable way to tell them apart. Most cases are benign and manageable, but any lump that changes quickly or causes pain deserves prompt evaluation. If you have a new or bothersome lump under your skin, we invite you to schedule a consultation at our Maitland office by calling (407) 389-2020.
