What are the other Names for this Condition? (Also known as/Synonyms)

• Desmoplastic Small Round Blue Cell Tumor
• DSRCT (Desmoplastic Small Round Cell Tumor)
• Mesothelioblastoma

What is Desmoplastic Small Round Cell Tumor? (Definition/Background Information)

• Desmoplastic Small Round Cell Tumor (DSRCT) is an extremely infrequent, aggressive soft tissue tumor
• It is regarded as a kind of high-grade malignancy that spreads and infiltrates into the surrounding tissues and organs. Generally, the outcome for an individual with this tumor is poor
• DSRCT usually affects young children and adults. These tumors are normally located deep inside the body tissues, with common sites being the abdomen and pelvis region. Other locations include the lung, scalp, hand, and pancreas
• Any combination of chemotherapy, radiation therapy, and invasive procedures, are used to treat DSRCT

Who gets Desmoplastic Small Round Cell Tumor? (Age and Sex Distribution)

• Desmoplastic Small Round Cell Tumor primarily affects young children (boys) and young men, in the 10-30 years age group. Middle-aged and elderly adults are typically not affected
• Males are much more affected than females. Some reports indicate a male-female ratio of 5:1, while others studies report a higher frequency in males with a male-female ratio of 9:1
• Caucasian males are known to be affected the most - no other specific racial or ethnic preferences have been observed

What are the Risk Factors for Desmoplastic Small Round Cell Tumor? (Predisposing Factors)

Risk factors for Desmoplastic Small Round Cell Tumor include:

• The risk of DSRCT is linked to certain genetic mutations caused by reciprocal chromosomal translocations, where an exchange of genetic material takes place between two chromosomes
• Some association with Wilm’s tumor and Ewing’s sarcoma have been observed

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases ones chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Desmoplastic Small Round Cell Tumor? (Etiology)

• The exact cause and mechanism of Desmoplastic Small Round Cell Tumor formation, is unknown
• They are thought to occur due to genetic defects (fused genes) occurring on account of certain chromosomal exchanges

What are the Signs and Symptoms of Desmoplastic Small Round Cell Tumor?

The presentations are based on the location of the tumor. Desmoplastic Small Round Cell Tumor signs and symptoms include:

• Most of the times, the abdominal cavity, pelvic, intestinal region, fat linings around the stomach and abdomen, are involved
• Other (rarely) affected regions include the skull, scalp, hand, pancreas, kidney, and ovary
• The soft tissue tumors grow at a moderate rate and then, suddenly start progressing rapidly. In most cases, the initial period of tumor growth is asymptomatic
• Due to large size of tumor in the stomach and abdomen, the adjoining organs, nerves, and muscles may be compressed or restricted. This leads to abdominal pain/cramps, sensation of mass in the stomach, and obstruction of the gastrointestinal tract. Often these signs may be the first indications of DSRCT
• Depending on the location, there could be other symptoms, which might include back pain, anemia, clotting of blood, chronic sinusitis, scoliosis, and hormonal changes (like, due to thyroid gland anomalies)

How is Desmoplastic Small Round Cell Tumor Diagnosed?

Diagnostic tests vary, based on location of the tumor. It is often noticed that at diagnosis, the tumor has metastasized to distant organs. Diagnosis of Desmoplastic Small Round Cell Tumor is made using the following tools:

• Physical examination, evaluation of patient’s medical history
• Histopathological studies conducted on a biopsy specimen - the specimen is examined under a microscope by a pathologist, to arrive at a definitive diagnosis
• MRI, CT, and PET scans of the affected regions - to aid in obtaining a clear image of the tumor prior to surgery. A solid and firm mass is usually noticed

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Desmoplastic Small Round Cell Tumor?

Complications are dependent on the site and severity of the Desmoplastic Small Round Cell Tumor. These include:

• Usually by the time DSRCT is detected, chances are that it would have proliferated and metastasized aggressively to other regions, thus damaging organs and tissues beyond repair
• Liver, lung, lymph nodes, and bones, are areas to where metastases commonly occurs
• Blood loss during invasive treatment methods may be heavy
• Damage to vital nerves, blood vessels, and surrounding structures, during surgery
• Side effects from chemotherapy (such as high toxicity), radiation therapy
• DSRCT is a frequently misdiagnosed tumor, as a result of which there could be a delay in correct treatment administration

How is Desmoplastic Small Round Cell Tumor Treated?

Treatment measures for Desmoplastic Small Round Cell Tumor include the following:

• A combination of chemotherapy, radiation therapy, and invasive procedures, are used to treat DSRCT
• Chemotherapy is administered initially, followed by surgical excision of the lesion. The surgical removal of entire lesion is challenging in most cases - considering the location, and late stage of tumor detection. After surgery, if required, radiation therapy is given
• Embolization is used to provide temporary relief from the symptoms, and reduce blood loss during a surgical procedure
• Bone marrow or stem cell transplants are performed in some individuals (as necessary)
• When the tumor is at an inaccessible location, or is unsafe for surgical intervention; non-invasive procedures may be adopted
• Post-operative care is important: A minimum activity level is to be ensured until the surgical wound heals
• Follow-up care with regular screening and check-ups are important, to watch for any metastatic behavior
• It is hoped that certain targeted medical therapies (such as immunotherapy) can be developed, based on research inputs from studying the genetic causes of DSRCT

How can Desmoplastic Small Round Cell Tumor be Prevented?

• Current medical research have not established a way of preventing Desmoplastic Small Round Cell Tumor
• Genetic testing of the expecting parents (and related family members) and prenatal diagnosis (molecular testing of the fetus during pregnancy) may help in understanding the risks better during pregnancy
• If there is a family history of the condition, then genetic counseling will help assess risks, before planning for a child
• Regular medical screening at periodic intervals with blood tests, radiological scans, and physical examinations, are mandatory for those who have been diagnosed with the tumor
• Due to its high metastasizing potential, often several years of active follow-up vigilance is necessary

What is the Prognosis of Desmoplastic Small Round Cell Tumor? (Outcomes/Resolutions)

• Desmoplastic Small Round Cell Tumor is a rare, but highly malignant cancer that is not completely understood
• The long-term prognosis depends on a combination of factors, such as:
  • Age of the individual
  • Tumor size and  stage at detection
  • Its location
• However despite intensive treatment and management of the condition, the prognosis remains very poor
• The short to medium-term outcome is dismal for most individuals (3-year survival rate is 44%, at 5-year is <15%), given the high metastasizing rate of the tumor (at about 40%)
• The best outcome is when the tumor is sited outside the abdomen/pelvic region and is detected early, while still in its initial stages

Additional and Relevant Useful Information for Desmoplastic Small Round Cell Tumor:

• The technique of removing a large part of the tumor mass in order to facilitate other treatment options, like chemotherapy and radiation, is called debulking surgery. This is practiced with Desmoplastic Small Round Cell Tumor, when the entire lesion cannot be surgically removed
• DSRCT consists of oval-spindle cells in a collagenous bed, and having a growth of fibrous tissue (termed desmoplasia)