Definition
A lipoma is often also called a fat tumor. It is a benign tumor of fat tissue cells (adipocytes) and is the most common type of tumor that develops from mesenchymal tissue. Lipomas are visible as a kind of lump under the skin, which consists of fatty tissue and is enclosed by a capsule of connective tissue.
Lipomas are harmless skin phenomena that some patients find disturbing for aesthetic reasons alone. They are usually benign soft tissue tumors. Only rarely do lipomas degenerate and become malignant and a problem.
They very often lie subcutaneously, i.e. directly under the skin. On the head, this type often occurs in the neck area. In contrast, most lipomas on the head are subfascial lipomas.
This means that the fat tumor is still under the fascia that surrounds each muscle individually. This type of lipoma usually grows at the transition from forehead to hairline and is a little more difficult to remove. Lipomas occur about 20 percent of the time on the head, making the head the most common site of predilection for their appearance.
Benign tumors, which include lipomas on the head, grow slowly and non-invasively, which means they do not metastasize. Lipomas are often asymptomatic and are only disturbing in that lumps under the skin become noticeable. Sometimes pressure pain can occur.
Although only a really very small percentage of lipomas degenerate, a dermatologist should be consulted for histological clarification. The dermatologist usually takes a biopsy and sends the tissue to a laboratory for clarification. Lipomas on the head can occur individually or in large numbers.
Why lipomas on the head occur is not known according to the current state of science. The causes are metabolic diseases such as diabetes mellitus or hyperuricemia (a high uric acid level in the body). Genetic predisposition can also play a role in the development, just as inheritance within the family is possible.
In neurofibromatosis, in addition to neurofibromas, lipomas also occur on the patient’s body. Since neurofibromatosis is a hereditary disease, the theory of hereditary disease is not so far-fetched, even if it has not yet been proven. The fact that pluripotent mesenchymal cells, which should actually differentiate into adipocytes, degenerate is also under discussion.
Every human being has pluripotent stem cells that develop into the many different individual cells found in the body. If not everything goes according to plan during this development in the embryonic phase, researchers suspect that adipocytes (fat cells) are created, which continue to divide and multiply, even without having received the corresponding signal from the body. Decoupled cells grow uncontrolled and lipomas are formed.
The diagnosis of a lipoma of the head is usually easy to make. In the beginning, patients often notice a small, rubber-like lump under the skin. Every bump or lump should be presented to a doctor so that he can rule out a malignant tumor.
Lipomas are clearly defined, easily displaceable tumors. In the very early stages, a hard area under the skin can be felt, which then grows into a lump or bump. Lipomas on the head are characterized by very slow growth and a final size of less than 5 centimeters.
This final size is often only reached after decades, if no action has been taken before. Such a bump on the head does not look very nice in the end. Of course, exceptions confirm the rule and there have been cases with larger lipomas.
Starting from a diameter of 5 centimeters one speaks of giant lipomas. Lipomas are usually located superficially under the skin. For a more exact clarification the doctor makes an ultrasound or an X-ray.
With both methods he can exclude other new formations such as cysts or fibromas from the outset. In some cases, a computer tomogram or magnetic resonance tomogram is also arranged, since in up to 50% of cases a thin septum can be seen between the lipoma and the surrounding tissue. The septum alone can confirm the diagnosis, it is a phatognomic symptom.
This means that as soon as this is visible, the diagnosis is confirmed. Even experienced doctors can only distinguish a benign lipoma of the head from a liposarcoma in 80% of cases. In controversial cases, the removal of a biopsy is therefore ordered.
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