Pathology

Liposarcomas can become very large and heavy depending on their location. Tumors weighing several kilograms are not uncommon. In extreme cases, they can weigh up to 30 kg.

First, a few words about the “macroscopic picture” of the tumor, i.e. how the tumor looks when seen with the naked eye. Often the tumor appears at first well encapsulated and limited, but occasionally no tumor metastases are found in the vicinity of the main tumor. Liposarcomas have a yellowish color (just like the fatty tissue itself) and a gelatinous-mucosal structure.

The tumor itself often contains necroses (dead cell areas), hemorrhages and calcifications.The histological (microscopic) image of the tumor is what is seen when the removed tumor is cut into fine layers and viewed under the microscope. When looking at the so-called sectional images, several subtypes can be distinguished. These subtype classifications are also used to estimate a prognosis.

Here, the degree of dedifferentiation is indicated. The higher the degree of dedifferentiation, the greater the difference between the degenerated tumor cells and healthy cells and the worse the prognosis for the further course. The “well-differentiated” (= little dedifferentiated) liposarcoma is the most common with 40-45%.

The cells differ only very little from mature healthy fat tissue. The dedifferentiation is low grade. Synonyms for “well differentiated” liposarcoma are atypical lipomatous tumor or atypical lipoma.

The “myxoid/round-cell” liposarcoma is the second most common with 30-35%. Dedifferentiation is already moderately to highly advanced. The “pleomorphic” liposarcoma has a 5% share of liposarcomas.

The dedifferentiation of the cells is highly advanced. The “Dedifferentiated” liposarcoma, as the name suggests, is also highly dedifferentiated. However, this occurs only very rarely.

Symptoms

Liposarcomas often remain asymptomatic for a long time and thus go unnoticed. Depending on the location, the symptomatology can vary. First of all, a slowly growing solid tissue mass is usually perceived.

Depending on how deep the liposarcoma is located, this tissue proliferation is noticed sooner or later. If the tumor develops, for example, in the retroperitoneum, it is usually diagnosed very late, since it is hardly noticed there. The main symptom of retroperitoneal tumors is abdominal discomfort (discomfort in the abdominal region), since the tumor begins to press on the organs as it grows in size.

On the limbs, the swelling is usually noticed quite early. If the tumor lies adjacent to nerve tracts, it can press on them as they grow and thus become conspicuous by pressure pain. If there are blood vessels in the vicinity, they may be compressed and this may cause discomfort to the blood flow in the affected region.

The larger the tumor becomes, the more likely it is that it will lead to functional limitations (for example, if there is a tumor in the thigh, the leg may no longer be able to bend completely). General symptoms, as they occur in many cancers, can also be present in liposarcoma. These include weight loss, night sweats, fatigue, tiredness, nausea and vomiting.

Liposarcoma usually causes pain only when the tumor constricts organs or pushes nerves. Depending on the location and size of the tumor, it can exert pressure on various organs, which is manifested by pain in the abdominal cavity. Pain can also occur when the liposarcoma compresses a nerve, which often causes tingling and numbness at the affected skin area.