Myolipoma is a benign tumor of fat and muscle tissue that occurs primarily in the abdominal and pelvic areas. The cause appears to be a genetic mutation that affects women more often than men. Treatment is equivalent to surgical excision.


What is myolipoma?

Tumors are distinguished primarily depending on the degree of their malignancy and the tissues involved. The myolipoma falls into the group of benign tumors. These are growths of mature fatty tissue and smooth muscle cells that occur primarily in the pelvic and abdominal areas. The prevalence is rather low. In a ratio of two to one, women are more often affected by myolipomas than men. See sciencedict for Introduction to Hyperparathyroidism.

In most cases, the benign tumors are relatively large. Since the growths do not tend to degenerate, myolipomas that are recognized late are also considered to have a favorable prognosis. Recurrences only occur in the rarest of cases. The cause of the development of myolipomas seems to lie in genetics. External factors for the tumor disease are not yet known.


A gene of human DNA is known as HMGA2. This gene codes for the protein of the same name, which takes on architectural tasks in the human body. For example, the protein is an essential component of higher protein complexes that appear as regulatory factors in transcription. The cases of myolipoma documented to date suggest a mutation in the associated HMGA2 gene.

Apparently, this mutation can correspond both to a deletion and to an incorrect composition of the individual components. Mutations in the HMGA2 gene result in an incorrectly constructed HMGA2 protein and a functional impairment of the associated protein complexes. Apparently, these complexes can no longer fulfill their regulatory role in transcription if the gene is mutated. In addition to myolipoma, diseases such as obesity are associated with mutations in the HMGA2 gene.

Symptoms, Ailments & Signs

Patients with myolipoma have macroscopically encapsulated, yellowish tumors with nodules or strands of light tan, fibrillar, or whorled tissue. If the tumor develops in the underlying soft tissue, its size is usually between ten and 25 centimeters. In the subcutaneous tissue, these are usually smaller lesions.

Histology shows mature adipose tissue and smooth muscle cells. The ratio is usually 1:2. Smooth muscle is often evenly distributed over the lesion and is endowed with a deeply eosinophilic fibrillar cytoplasm. The fabric pattern looks like a sieve. Atypia or mitotically appreciable activities are not observed in either the muscle or the fat component of the tumors.

Fibrosis and inflammation can occur in adipose tissue. Any symptoms that patients with a myolipsoma may experience result from these phenomena. Due to the inflammatory components, conceivable symptoms include burning or slightly aching pain.

Diagnosis & course of disease

In many cases, myolipsomes are palpable findings. This applies in particular to tumors in the subcutaneous tissue, which can be palpated particularly easily from a certain size. To make a diagnosis, the doctor usually takes a biopsy of the tissue and has this biopsy analyzed histologically. The histology shows minimal division behavior and is free of atypes.

Immunohistochemically, the smooth muscle portion of the myolipoma shows a diffuse strong positivity for actin or desmin. Sometimes expressions of estrogen or progesterone receptors can be detected. The melanocytic HMB45 marker plays a particularly important role in differential diagnosis. This marker is positive for angiomyolipoma, which looks similar.

In contrast, it is negative for myolipoma. The prognosis for a myolipoma is extremely favorable. The tumor is benign and does not tend to degenerate even after years. Once the growth is completely removed, it usually does not recur.


In most cases, the myolipoma does not lead to any particular complications or life-threatening conditions, since it is a benign tumor. However, those affected can suffer from various inflammations and infections, so that the quality of life is significantly restricted by this tumor. Those affected also often suffer from fever and pain in the affected areas.

If the pain also occurs at night as rest pain, it can also lead to sleep disorders and thus to depression or other mental illnesses. General irritability of the patient is also not uncommon. The pain is usually burning.

It is not possible to treat the myolipoma causally because it is a genetic defect. However, there are various therapies available to those affected that can limit the symptoms. There are no particular complications. In some cases, the growth can also degenerate, and removal is necessary in any case.

If treated early, the life expectancy of the affected person will not be reduced by this disease. In most cases, no further complications arise. The risk of degeneration is relatively low.

When should you go to the doctor?

Tumor diseases such as myolipomas must always be diagnosed and treated at an early stage. Anyone who notices nodules, lesions, sensory disturbances and other signs of a tumor should see their family doctor. If accompanying symptoms such as increasing pain or hormonal problems occur, a doctor must be consulted immediately. Although myolipoma is a benign disease, serious complications can occur if it is not treated or treated too late. At the latest, if other symptoms such as inflammation or infections occur in connection with a lump, the doctor must be informed.

The family doctor can already make an initial diagnosis based on a physical examination. Further treatment is carried out by a specialist, such as a dermatologist or an internist. Regular visits to the doctor are necessary during treatment, as there is a risk that the growth will degenerate. For this reason, check-ups must be carried out regularly after the therapy has been completed. Parents who notice symptoms of a tumor in their child should contact the responsible pediatrician immediately.

Treatment & Therapy

A causal therapy is not available for myolipoma. The proliferation appears to have genetic origins and is associated with mutations in the HMGA2 gene. Therefore, a gene therapy approach would have to be pursued for the causal therapy. These therapeutic approaches are a current subject of research, but have not yet reached the clinical phase.

For this reason, myolipomas can only be treated symptomatically so far. The focus of this treatment is excision. Surgery is performed to remove the tumor. The surgical procedure for myolipomas of the subcutaneous tissue is usually less invasive than for those of the deeper soft tissues. The growth should be removed as completely as possible in order to rule out recurrences, which are rare anyway.

Given the low risk of degeneration, many patients of the myolipsoma tend to refuse the operation. Nevertheless, the doctor should clearly and unequivocally recommend the operation. Despite the low risk, degeneration can theoretically take place. Therefore, only the complete removal of the tumor gives patients security.

Although the tumor grows at a slow rate, growth does take place. This fact also speaks in favor of surgical excision, since the proliferation above a certain size could cause more or less unpleasant symptoms.

Outlook & Forecast

Myolipoma is a benign lesion. After surgical removal of the myolipoma, there is no risk of recurrence. In addition, the lesion does not degenerate and can be treated relatively well. The prognosis is accordingly positive. However, a prerequisite for a good prognosis is early treatment by a specialist.

If surgical removal of the tumor is not possible, for example because the myolipoma is close to sensitive organs or arteries, the prognosis is less positive. Under certain circumstances, an attempt can be made to treat the condition with chemotherapy. Normally, however, this is not very promising either, since various symptoms and complications can occur during chemotherapy, which must be taken into account. The exact prognosis can only be made by a doctor.

As a rule, however, the prognosis and prospect of a full recovery from a myolipoma is comparatively good. Assuming early therapy, the myolipoma should be able to be completely removed without any further symptoms to be expected. Affected people are best advised to speak to their doctor, who can give details of their outlook and prognosis.


So far, no external factors are known for the development of a myolipoma. Only if such factors existed could promising preventive measures be available. Although a genetic analysis or mapping can provide information about the personal risk of developing a myolipoma, it is not necessarily to be understood as a preventive measure.


In the case of a myolipoma, the patient usually only has a few and limited options for direct follow-up care. For this reason, sufferers of this disease should ideally consult a doctor very early on in order to prevent further symptoms or complications from occurring. As a rule, no self-healing can occur, so that the patient is always dependent on medically controlled treatment.

The sooner a doctor is contacted, the better the further course of this disease is usually. In many cases, this disease can be removed with a minor surgical procedure. The person concerned should definitely rest and rest after such an operation, whereby exertion or stressful and physical activities should be avoided.

Likewise, the body should not be unnecessarily burdened. Regular check-ups by the attending doctor are also necessary after the procedure. The disease itself does not reduce the life expectancy of the patient, and no further follow-up measures are necessary. A scar may be left behind, which in some cases can be healed.

You can do that yourself

Patients with a myolipoma should examine their body daily for the presence of irregularities or the formation of lumps. This helps with early detection and thus rapid treatment. The sooner the tumors can be detected, the better the treatment options are. These result in a small number of complications as well as sequelae. Any growths discovered should therefore be discussed with a doctor as soon as possible.

The body weight should always be within the normal range of the BMI. The nodules develop primarily in the fatty tissue of the affected person. The more pronounced the fat tissue is, the more difficult it is to detect the tumors early by palpating the skin. It is advisable to lose excess weight as part of self-help. This enables a quick diagnosis and an early detection of irregularities. By changing the food intake and controlling the necessary calories consumed, weight can be reduced independently. Sufficient exercise and sporting activities also help to reduce excess weight.

If there are people in the family who are already suffering from myolipoma, regular check-ups are advisable. Although the genetic disease cannot be cured with current medical options, early detection can be optimized through comprehensive information about the further course of the disease.