A lipoma is a common, benign growth of mature fatty tissue that develops just beneath the skin. Patients who choose to have them removed frequently ask whether the lump will return. Understanding the nature of a lipoma and the specifics of its removal clarifies the low probability of a true recurrence.
What Exactly Is a Lipoma
A lipoma is a soft tissue tumor made up of mature fat cells (adipocytes) encapsulated by a thin, fibrous layer of tissue. They are the most common noncancerous soft-tissue tumor found in adults, often appearing between the ages of 40 and 60. They usually present as a soft, doughy lump that is movable and easily compressed, distinguishing them from firmer masses. Most lipomas measure less than two inches in diameter, though they can occasionally grow larger.
The exact cause for a lipoma’s formation remains unclear, but a genetic predisposition plays a role in many cases. The majority of these growths are painless, rarely causing discomfort unless they press against a nearby nerve or joint. Lipomas can appear anywhere fat is present, but they are most commonly found on the back, trunk, neck, and shoulders. They are considered benign, meaning they are not cancerous and do not spread.
Surgical Removal and The Likelihood of True Recurrence
The primary treatment for lipomas that are symptomatic, large, or a cosmetic concern is surgical excision. This involves making an incision to completely cut out the lipoma, including the fibrous capsule. When a lipoma is removed in its entirety, the risk of a true recurrence at that surgical site is extremely low, generally ranging between 1% and 5%.
The completeness of the excision is the most important factor in preventing the lipoma from regrowing. Recurrence after traditional surgery is usually a direct result of residual lipoma tissue or capsule fragments being left behind. Deep-seated lipomas or those in complex anatomical locations pose a greater challenge for the surgeon, which can slightly increase the risk of incomplete removal.
Less invasive techniques, such as liposuction, are sometimes used to remove the fatty tissue through a small incision, resulting in a more favorable cosmetic outcome. However, because liposuction uses a cannula to suction out the fat, it is more difficult to ensure the complete removal of the surrounding fibrous capsule. While recurrence rates after liposuction are low, the risk of the original lipoma regrowing may be slightly higher compared to full surgical excision.
When Lipomas Reappear New Growth vs Incomplete Removal
When a lump reappears in the same general area after removal, it is usually a new lipoma forming rather than the original one truly growing back. A true recurrence is a rare event following complete excision, resulting from incomplete removal of the original tumor. The more common scenario is the formation of a separate, new lipoma due to the individual’s underlying tendency to develop these growths.
This phenomenon is common in individuals with a genetic predisposition, such as those with familial multiple lipomatosis (FML). FML is a hereditary condition where patients are prone to developing numerous lipomas across the body over their lifetime. For these patients, removing one lipoma does not prevent the body from forming others nearby or in different locations.
The appearance of a new growth should prompt a consultation with a healthcare provider, especially if the lump exhibits atypical characteristics. While lipomas are benign, rapid growth, pain, or a firm, fixed consistency can suggest a less common or deeper form of fatty tumor. In rare instances, these signs may point toward a liposarcoma, which is a malignant tumor of fat cells.