What Is Intramuscular Lipoma?

Lipoma is a common benign tumor of soft tissues. It is composed of mature fat cells and can occur in any part of the body that has fat. Occurs on shoulders, back, neck, breasts, and abdomen, followed by proximal extremities (such as upper arms, thighs, buttocks). It is mainly subcutaneous and is called superficial lipoma. It is also found between the deep part of the limb and the abdomen of the muscle. It is called deep lipoma. Patients are older, more common in middle-aged people aged 40 to 60, and less common in children. Deep lipomas mostly grow along the muscles and can reach the periosteum, but rarely invade adjacent bones. Lipomas are rarely malignant and can be easily removed by surgery.

Basic Information

English name

Lipoma

Visiting department

surgical

Common causes

Abnormal mutation of genes, leading to adipose tissue deposition

Common symptoms

Longer than the trunk, limbs and abdominal masses, clear boundaries, soft

Causes of lipoma

The etiology of lipomas is not completely clear at present, and may be related to factors such as inflammation-stimulated connective tissue degeneration, abnormal adipose tissue metabolism and disorders, abnormal secretion of anterior pituitary gonadotropins, congenital dysplasia, and intestinal malnutrition. About 1/3 of patients with multiple lipomas may have a family history.

There is a "lipoma tumorigenic factor" in the human body. Under normal circumstances, this tumorigenic factor is in an inactive state (inactive state) and does not normally develop disease, but under the influence of various internal and external environmental factors, this lipoma tumorigenic factor is active. With a certain activity, when the body's resistance decreases, immune cells such as lymphocytes and monocyte phagocytic cells in the body's ability to monitor tumorigenic factors decline, coupled with changes in the internal environment of the body, chronic inflammation stimulation, body fat Under the inducement conditions such as metabolic abnormalities, the activity of lipoma tumorigenic factor is further enhanced to combine with certain gene fragments in the normal cells of the body to form abnormal gene mutations, which causes a normal proliferation of normal adipocytes and surrounding tissue cells, leading to adipose tissue A mass that deposits and protrudes toward the body surface or individual internal organs, that is, a lipoma.

Clinical manifestations of lipoma

Superficial lipomas cause almost no symptoms except for localized masses. Can be single or multiple shots, ranging in size from a few millimeters to tens of centimeters. The tumor grows slowly, the texture is soft, the boundary is clear, and it is lobulated. The movement is good, and the skin can be sunken. Rarely causes pain, and pain is often a late symptom caused by a large lipoma compressing the peripheral nerves.

Deep or subfascial lipomas can cause a variety of symptoms, depending on their location and size. Such as surgical lipoma can cause stagnation or limited activity. Larger mediastinal lipomas can cause dyspnea or palpitations.

Lipomas are common in obese people, and their volume increases with rapid weight gain, but in contrast, lipomas do not shrink with severe weight loss.

Lipoma examination

Imaging examination

According to the site of lipoma, ultrasound examination, CT examination, magnetic resonance examination can be selected. Ultrasonography is very helpful for diagnosis. Lipomas appear as round, light-transmitting masses. Due to the high density of surrounding tissues, they can be clearly displayed. The location, size, texture, and blood supply of the tumor can be judged. CT showed a mass characteristic of subcutaneous adipose tissue. The NMR T ₁ weighted image shows a high signal.

2. Pathological examination

Pathological examination showed a pale yellow section with a complete thin fibrous envelope with fatty lobules separated by trabeculae. Tumor cells are mainly mature adipocytes, with a few adipocytes occasionally. Generally, there are not many blood vessels in the tumor, and focal mucus degeneration, calcification or ossification is sometimes seen.

Lipoma diagnosis

The diagnosis of the disease is mainly based on clinical manifestations and related examinations. Superficial lipomas can usually be diagnosed by physical examination. Deep lipomas can be diagnosed by combining imaging and pathological examinations.

Lipoma treatment

Solitary lipomas with a diameter of 1 cm generally do not require treatment. Larger patients can be surgically removed. Deep lipomas are sometimes difficult to completely remove and can recur locally, but basically no malignant changes occur. The treatment of multiple lipomas is also based on local resection.