What Is Desmoplastic Small round Cell Tumor?

A desmoplastic small round cell tumor, which is sometimes called a mesothelioblastoma, is a type of soft tissue sarcoma usually seen in young males. This type of cancer is extremely aggressive and difficult to treat, and the five year survival rate is poor. This type of cancer usually originates in tissues inside the abdomen, but by the time the cancer is discovered, it has often metastasized to the lungs, bones, lymph nodes, or brain. Doctors are not sure what causes this type of cancer, though a rare genetic marker can help in making a positive diagnosis.

A rare form of cancer, a desmoplastic small round cell tumor is most likely to develop in adolescents and young adults. Of the patients who develop this cancer, 90 percent are male, and 85 percent are caucasian. The disease can affect any person at any age but is rarely seen in a person over the age of 30.

In most cases, a desmoplastic small round cell tumor is found in the lining of the abdomen. These tumors can develop in any part of the body, however, including the kidneys, reproductive organs, skin, and pancreas. They can be uniformly or erratically shaped, though for the most part, they appear as light-colored roundish balls and can be found individually, in clusters, or in lines. By the time these tumors are found, they are often quite large and may have a diameter of 3.9 inches (10 centimeters) or more.

Symptoms of this type of cancer may not be noticed until a desmoplastic small round cell tumor grows large enough to interfere with bodily functions or the cancer spreads to other parts of the body. The tumors themselves can cause pain and discomfort or gastrointestinal problems. Occasionally, they may spread through the abdominal lining and form a swollen spot on the surface of the skin. When this cancer is discovered, it has often spread to other systems, some of them distant from the original site of the tumor.

Treatment for patients who have a desmoplastic small round cell tumor is difficult and not often effective. The tumors are often large and there can be many of them spread throughout the abdomen, making it difficult to remove them surgically. They also have the properties of a number of different types of cancerous cells, making them resistant to treatments involving radiation and chemotherapy. Only about 15 percent of patients diagnosed with this form of cancer will live for 5 years or more.