Liposarcoma: Types, Symptoms, Causes, Diagnosis & Treatment

A rare type of soft tissue cancer, liposarcoma arises from the fat tissue. Liposarcoma can affect any part of the body but, the majority of the cases involve thighs and the abdominal cavity. The tumour affects the connective cells such as the thigh, legs, abdomen, behind the knee and can be found in other parts of the body such as the retroperitoneum areas. The soft tissue cancer very rarely affects your skin and the triggering element causing the growth of the tumorous ^[1] cells is still ambiguous.

Under the microscope, the soft tissue sarcoma mirrors the fat cells. Mostly, liposarcoma tends to affect adults between the age of 40 and 60 ^[2] but is not just limited as it can occur at any age. In the case of children, liposarcoma occurs during the teenage ^[3] years. In adults, liposarcoma is the most common soft tissue sarcoma.

Normally liposarcoma arises as a painless, slowly enlarging, non-ulcerated submucosal mass but there have been cases that have seen the rapid growth ^[4] of the lesions. This type of tumour does not usually arise from a pre-existing condition. Liposarcoma does not grow from the submucosal or subcutaneous fat but from the deep-seated stroma. Malignant in nature, liposarcoma can spread throughout your body including your vital internal organs and tissues.

It is not possible to prevent the onset of liposarcoma - the only way to lower the risk of liposarcoma development is by avoiding the related risk factors. Likewise, in the case of lack of treatment, the tumour will erode into the surrounding tissues, resulting in it becoming fatal ^[5] and life-threatening.

What Are The Types Of Liposarcoma?

According to the study conducted by the World Health Organisation ^[6] , the five categories of liposarcoma are well-differentiated liposarcoma, de-differentiated liposarcoma, myxoid liposarcoma, round cell liposarcoma and pleomorphic liposarcoma. Considering the biological form, liposarcoma is classified into three types such as well-differentiated liposarcoma, myxoid or round cell liposarcoma and pleomorphic ^[7] liposarcoma.

However, the four main types of liposarcoma which have been commonly diagnosed and reported are:

1. Well-differentiated liposarcoma

WDLS or well-differentiated liposarcoma is the most common type of malignant tumour. It is slow growing and looks similar to the fat cells. A low-grade tumour is painless and tends to grow and change. The tumour ^[8] is usually located in the limbs or the retroperitoneum and is composed of proliferating mature adipocytes.

2. Myxoid or round liposarcoma

The second most common type of liposarcoma, myxoid or MLPS accounts for about 30% to 35% of all liposarcomas. MLPS is characterised by its oval or round (mostly) mesenchymal cells and mostly occurs in adults. But studies have revealed that myxoid liposarcoma, in comparison to the other types of liposarcoma affects teenagers ^[9] more frequently.

3. Pleomorphic liposarcoma

It is the rarest but the most aggressive form of liposarcoma and is classified as being a heterogeneous ^[10] group of tumours. Under the microscope, pleomorphic cells look very different from that of the normal cells. PLS is fast growing in nature and is located in the soft tissues of the upper and lower extremities.

4. De-differentiated liposarcoma

De-differentiated liposarcoma is a high-grade tumour ^[11] and is the least common subtype of liposarcoma. It usually arises from the well-differentiated liposarcoma, that is, when a low-grade tumour shifts from low grade to high grade.

What Are The Symptoms Of Liposarcoma?

In the initial stages of the tumour, the symptoms tend to be less prominent, therefore resulting in the patients realising the onset of the disease only when the tumour aggravates.

Likewise, most people who have the cancerous tumour growth does not feel sick or any pain. The only indicator of the tumour is a slowly growing lump, which is often left unnoticed. As mentioned, the symptoms ^[12] vary according to the affected part of the body.

1. In the arms & legs

• swelling
• pain
• weakness of limb^[13]
• a growing lump of tissue under the skin.

2. In the abdomen

• abdominal swelling
• abdominal pain ^[14]
• constipation
• bloody stool
• trouble in urinating
• weight gain
• bloating.

What Are The Causes Of Liposarcoma?

The exact cause of liposarcoma stays ambiguous. Even though there is no definite clarity on the causing factor, doctors and researchers have enough information to point out that liposarcoma is caused when there is an error ^[15] in the DNA.

Liposarcoma is developed in the body in the event of an error or mutations in the fat cells' genetic code. The rapid accumulation of the fat cells due to the mutation causes the cells to multiply, resulting in the formation of a mass or tumour of abnormal cells.

How Is Liposarcoma Diagnosed?

The nature of liposarcoma and the impact it can have on the human body is severe. It is critical that you go to a doctor if you are facing the above-mentioned symptoms because, if left untreated - it is fatal! Your doctor will perform a number of tests to analyse and examine your condition.

1. Physical examination

The first and foremost step taken by the medical practitioner in diagnosing liposarcoma is the physical examination. During the examination, the doctor will examine if the lump ^[17] growths are larger than 5cm and deep-seated, firm and fixed.

2. Imaging tests

The step following the physical examination would be imaging tests. Under this process, the doctor will recommend tests such as X-ray, CT scan and MRI to determine the size and extent of the liposarcoma growth.

3. Biopsy

Under this process, the doctor will remove some of the suspicious tissue from your body. It is carried out through a surgery or using a syringe and a needle.

4. Advanced lab tests

The lab tests are conducted to analyse and examine the cancerous cells in depth. Pathologists, that is, doctors specialised in blood and body tissue analysis will study the extracted samples using laboratory tests such as molecular ^[18] genetic testing, cytogenetic analysis, immunohistochemistry and fluorescence in situ hybridization.

What Are The Treatment Options For Liposarcoma?

In accordance with the location, type and size of the tumour, the treatment of liposarcoma varies.

1. Surgery

The mostly followed treatment option for liposarcoma is surgery. The primary and central goal of surgery is to remove all of the cancer cells, often attempting to remove the entire tumour of liposarcoma. Surgery is optimal for cases where the tumour ^[19] has not spread to other organs. In most cases, amputation is the answer as it is the best way to remove cancer completely. In the case of limbs, legs and arms, surgery is successful whereas it is not the same for abdominal liposarcoma.

In some severe cases where the tumour is located near vital organs, surgery is critical. Therefore resulting in the surgeons adopting other methods.

2. Radiation therapy

Using powerful beams such as X-rays and protons, radiation therapy kills the cancer cells. Radiation therapy is used when the surgery fails to remove all of the cancer cells so as to prevent the regeneration or recurrence of the tumour ^[20] cells. Radiation is also used to shrink the tumour cells to make it easier for the surgeon to remove it.

3. Chemotherapy

In chemotherapy, drugs are used to kill the cancer cells. Although the role of chemotherapy in treating liposarcoma is not clearly stated, it is recommended for cases that are extremely severe and high chances of possible recurrence.
A close examination of the tumour cells will decide the need for chemotherapy to treat liposarcoma. It is often combined with radiation ^[21] therapy.

What Are Liposarcoma Risk Factors?

The following have been categorised as being the risk factors ^[16] of liposarcoma

• a damaged lymphatic system
• a history of radiation to the abdomen or any other body parts
• certain family (genetic) cancer syndromes such as Gardner syndrome or neurofibromatosis
• exposure to cancer-causing chemicals such as dioxin, vinyl chloride etc.

Liposarcoma Vs Lipoma

There is a common misconception among the masses that liposarcoma and lipoma are the same. Studies have revealed that people often believe lipoma gradually changes or grows into liposarcoma, the cancer. Although both ^[22] of the diseases has few similarities in the nature and treatment of the tumours.