A retroperitoneal tumor is a rare, abnormal growth that develops within a part of the abdominal cavity known as the retroperitoneal space. Because the retroperitoneal space is hidden toward the back of the abdomen and the organs are quite mobile, a retroperitoneal tumor can grow quite large, displacing organs out of its way, before it is discovered. Symptoms like an enlarged tummy and abdominal pain may eventually develop. Although retroperitoneal tumors can be benign or harmless, most of the time they are cancerous. Surgical removal is the most common treatment, although tumors can recur.
The peritoneum is a thin sheet of tissue that lines the inner walls of the abdomen, covering and enclosing the abdominal organs. At the back of the abdominal cavity is an area where the peritoneum does not completely enclose the organs, and this is known as the retroperitoneal space. The kidneys, adrenal glands, large blood vessels, and parts of the intestine are found in this space, where they are only covered by peritoneum on one side. As a retroperitoneal tumor develops, it can affect any of these retroperitoneal organs by pushing them out of place, crushing them, or invading their tissues.
Diagnosis of a retroperitoneal tumor usually involves a CT or MRI scan, which can show a picture of the growth and its effect on surrounding structures. Most often, the type of tumor is what is known as a sarcoma, which arises from the soft tissues of the body, such as the skin and muscles. A retroperitoneal sarcoma is cancerous, and a patient's outlook depends on whether the tumor can be completely removed and whether it has grown into surrounding organs or spread to other areas of the body.
If a tumor is cut out completely before it has had a chance to spread, the patient will have a more positive prognosis, although there is still a chance of recurrence. Some tumors invade major blood vessels and nerves, and this can make it impossible to completely remove them. When a retroperitoneal tumor grows in one of the kidneys, the kidney may be removed. Patients can survive if the remaining kidney is functional.
In addition to surgery, methods such as radiation therapy can be used to treat a retroperitoneal tumor. Radiation therapy is usually given before or after surgery to shrink the tumor or to kill any cells left behind after an operation. Chemotherapy has not been shown to work in treating this type of tumor, although research is ongoing.