Lipoma: Symptoms, Causes, Treatment

The skin is an organ that protects the body against external factors such as heat, light, microorganisms, and injury. Acting as a vital barrier for organs, the skin helps maintain body temperature, receive various signals from the environment, and provide immune system defense. The thickness and texture of the skin can vary among individuals. However, all humans have skin composed of three layers. The outermost layer of the skin is the epidermis, which contains melanocytes that give color to the skin. Beneath the epidermis lies the dermis, which houses sebaceous glands, hair follicles, nerve endings, and sweat glands. The innermost layer, the hypodermis, is a fatty tissue where body fat is stored. Each layer can have different functions. The sebaceous glands in the dermis are small glands that help reduce fragility by covering hair follicles. The lumps that occur due to the excessive growth of cells in this fatty tissue are called lipomas. Lipomas can form in any area where fat cells are present, and they are generally benign and usually harmless. Known as "lipomas," these lumps are painless, mobile, and fatty. They typically occur in adults aged 40-60 years. The formation of cancerous lipomas is rare and is referred to as "liposarcoma." Dermiste bulunan yağ bezleri kıl köklerini kaplayarak kırılganlığı azaltmaya yardımcı olan küçük bezlerdir. Bu yağ dokusundaki hücrelerin aşırı şekilde büyümeleri sonucu oluşan yumrulara yağ bezesi denir. Yağ hücrelerinin bulunduğu her bölgede oluşabilen yağ bezesi iyi huylu ve genellikle zararsızdır. “Lipom” olarak bilinen yağ bezeleri ağrısız, hareketli ve yağlı yumrular şeklindedir. Genellikle 40-60 yaş yetişkinlerde görülebilir. Kanserli lipom oluşması nadirdir ve “liposarkom” olarak adlandırılır (1, 2).

What is a Lipoma?

A lipoma is a soft, painless benign fat tumor that can form in any part of the body. They can vary in size, typically ranging from 1 to 10 cm. They can occur in subcutaneous fat tissues distributed throughout the body, but the most common locations are the back, neck, trunk, shoulders, and arms. Lipomas can easily move when touched and are generally painless. They grow slowly and usually do not cause cancer. These benign tumors typically occur in middle-aged individuals.

The exact cause of lipomas is still unknown. It is widely believed that the common cause is related to trauma and cytokine release. Some individuals may develop multiple lipomas, which may be indicative of certain syndromes. Since the subcutaneous fat tissue is present throughout the body, lipomas can form in any region. However, the most frequently seen areas may be the neck, shoulders, back, chest, and arms. In some cases, lipomas may grow inward in the body and may go unnoticed. Typically, one or two lipomas may form, but due to hereditary conditions such as familial lipomatosis, multiple lipomas can occur.

What Causes Lipomas?

The underlying cause of lipoma formation is not definitively known. Factors such as trauma and genetic disorders have been shown to be influential in the formation of lipomas. Additionally, the frequency of lipomas may increase in cases of obesity, diabetes, and hyperlipidemia. Some conditions that may cause lipoma formation include:

• Familial lipomatosis: Lipomatosis present in the family is hereditary and can particularly trigger the formation of multiple lipomas.
• Dercum's disease: Also known as Anders syndrome, this is a rare condition that can lead to painful lipoma formation in the arms, legs, and torso.
• Madelung disease: A health issue characterized by benign symmetric lipomatosis, Madelung is where multiple lipomas form around the neck and shoulders.
• Gardner syndrome: Rarely observed, Gardner syndrome can trigger the formation of lipomas and several other conditions.
• Cowden syndrome and Bannayan-Riley-Ruvalcaba syndrome: These are diseases caused by genetic mutations that can increase the risk of developing lipomas.

Lipoma formation can be hereditary, and having family members with lipomas may increase the likelihood of developing them in other individuals.

What Are the Symptoms of Lipomas?

Lipomas can form anywhere in the body and may sometimes go unnoticed. However, typical symptoms of a lipoma may include:

• Located just beneath the skin in a capsule shape,
• Generally oval or round in shape, found on the neck, shoulders, back, chest, arms, and thighs,
• Usually smaller than 5 cm but can grow up to 10 cm,
• Non-spreading, soft, and movable when touched,
• Grows slowly,
• Painless masses may indicate lipomas.
  Although lipomas are mostly painless, they can be somewhat painful when they exert pressure on nerves or form near joints. Additionally, lipomas may restrict certain movements.

How Are Lipomas Diagnosed?

Lipomas are masses that can be diagnosed through physical examination. Because lipomas can be confused with cysts, imaging tests may be conducted. Ultrasound, MRI, and computed tomography (CT) can be used to visualize the lumps and check for the presence of cysts. Cysts are typically located closer to the skin surface and can be firmer compared to lipomas. However, the location of the lipoma, its proximity to blood vessels and nerves, and whether it is causing pressure can be evaluated. Abnormally located lipomas can be visualized with ultrasound, MRI, and CT.

The pain level of the lipoma can be assessed, and a biopsy may be performed if there is suspicion of cancerous transformation. A tissue sample can be taken from the lipoma and sent to the laboratory. Liposarcomas are cancerous tissues that may resemble lipomas. Unlike lipomas, they can exhibit rapid growth, may be painful, and can form in a fixed manner.

What Are the Types of Lipomas?

Lipomas are primarily composed of adipose tissue but can be classified into subclasses based on their appearance. This variation may result from some lipomas containing different tissues and blood vessels. The types of lipomas can be described as follows:

• Conventional: Commonly seen white lipomas.
• Hypernoma: Lipomas originating from brown adipose tissue, which plays a role in regulating body temperature.
• Fibrolipoma: Lipomas that contain both fat cells and fibrous tissues.
• Angiolipoma: Lipomas that include adipose tissue and blood vessels.
• Myelolipoma: Lipomas that contain tissues producing blood cells and adipose tissue.
• Mile cell lipoma: Long rod-shaped lipomas.
• Pleomorphic lipoma: Lipomas containing lumps of varying sizes and shapes.
• Atypical lipoma: Lipomas consisting of numerous and deep adipose tissues.

Are Lipomas Cancerous Cells?

Lipomas are typically not cancerous cells. They are slow-growing, painless, and benign tumors. They can be hereditary masses. Generally, benign lipomas rarely transform into cancer. However, this is not common and may present additional symptoms.

Can Lipomas Transform into Cancer?

Lipomas can often present as benign. After their formation, lipomas usually have a low potential for change. Therefore, the likelihood of them transforming into cancer is considered low. However, if a lipoma grows rapidly, is painful, or continues to grow, suspicion of cancer may arise. Rarely, lipomas can transform into a type of cancer known as liposarcoma. This condition can be diagnosed with additional tests, and appropriate treatment can be provided.

Lipoma Treatment

Lipomas are generally lumps that do not require treatment. However, they can raise aesthetic concerns and negatively affect social life. Therefore, the removal of lipomas may be requested. Lipomas can be removed either through liposuction or surgically. Surgical removal is a safe procedure performed on an outpatient basis. Some individuals may prefer liposuction over surgery, which can be performed using a long and thin needle to remove the fatty lumps. When no procedure is necessary for the removal of lipomas, regular doctor visits may be required. Regular check-ups can monitor any changes in the tumors.

Surgical Treatment of Lipomas

Complete removal of lipomas can be achieved through excision (surgical removal). Before the procedure begins, the area where the tumor is located is numbed with local anesthesia. General anesthesia may be preferred for very large lipomas. After anesthesia is administered, an incision is made around the tumor, and the lump is removed. Typically, superficial and small lipomas can lead to discharge on the same day after removal. Stitches can be removed within a few weeks, and there may be a possibility of scarring. The recovery time to return to daily life can vary depending on the size and location of the lipoma. Recurrence of lipomas after removal is rare. In the presence of recurrent lipomas, excision treatment can be repeated. After the surgical procedure, bleeding, infection, redness, pain, and swelling may occur.