A lipoma is a benign tumor consisting of fat that usually causes no complications. It is primarily embarrassing for the person affected aesthetically when it is located at the skin. The origin of the formation of this type of tumor is not well known. This pathology mainly affects adults between 40 and 60 years old. Treatment, when necessary, is surgery.
It comes in the form of a soft ball to the touch. The fat present on the inside is exactly the same as normal subcutaneous fat. Of variable size, it can appear on different parts of the body: in particular on the neck, the torso, the arms or the breasts, when it is a cutaneous lipoma. But it can exist almost anywhere inside the body (stomach, lungs, brain, liver, etc.). It is a benign tumor progressively evolving. Unlike malignant tumors, the cells of a lipoma do not migrate to other organs and do not form metastases. They are usually small, and 80% of them are less than 5 cm, the others do not exceed 10 cm.
The types of lipoma and their variants:
- Subcutaneous lipomas: tumors that look like soft fat balls under the skin. This is the most common form.
- Other benign lipomas are much less common. It can be:
- Benign mesenchymoma.
- Lipoblastoma: occurring in infants or children under 3 years of age.
- Pleomorphic lipoma: especially in men over 45 years.
- Heterotopic lipomas: These are lipomas containing fat cells associated with other types of cells, from other tissues. It can be intramuscular lipomas, arboreal lipomas, neural fibrolipomas, parosteal lipomas …
- Hibernomas : These are lipomas formed from a particular fat, brown fat.
- Malignant tumors of the family of lipomas.
They are much rarer than benign lipomas:
- Liposarcoma that can be well differentiated, or dedifferentiated .
- Myxoid liposarcoma.
- The pleomorphic liposarcoma.
Cause of lipoma
When a lipoma occurs, it is because the fat cells or adipocytes have multiplied there. The origin of this proliferation of cells storing fats remains unexplained. The genetic factor ( heredity ) seems to play a role in their occurrence, but the trigger mechanism and other factors involved are unknown. Their evolution towards spontaneous healing is also a mystery.
Some people may have lipomatosis : in this case they have several lipomas on the body.
What are the symptoms of lipoma?
The manifestations of a lipoma may vary depending on the type of lipoma and its location. On examination, a lipoma is a ball of soft or elastic consistency, well defined, and of variable size. Sometimes the tumor is accompanied by pain. The pains are quite rare, they result from the compression of other tissues located nearby.
What is the diagnosis of lipoma?
The observation and palpation of a soft ball on an area of the body may direct the doctor or dermatologist to a lipoma. A lipoma is a mass of soft or elastic consistency and mobile relative to the surrounding structures, non-inflammatory and well defined. When it is superficial, an ultrasound makes it possible to make a diagnosis and to know if there is a risk that it turns out to be cancerous. In the case of deep lipomas, an MRI may be necessary.
A biopsy confirms the diagnosis: a tumor fragment is removed and analyzed.
What are lipoma treatments?
The choice of treatment depends on the nature of the lipoma and its location. If the lipoma does not cause any discomfort, it does not require any particular treatment.
However, it is advisable to monitor a lipoma that is not operated to observe if it does not grow, or if it becomes annoying.
Treatment of an annoying lipoma results in surgery, liposuction, or lipoma ablation (lipectomy). When a lipoma is operated, it is then systematically sent to a laboratory for analysis.
Liposuction has fewer scars, but leaves the lipoma envelope in place and is at risk of recurrence.
In the case of many subcutaneous lipomas, or of anyone unable to undergo surgery, an alternative is to inject corticosteroids into the lipoma so as to reduce the volume.