Dear Dr. Roach: My husband is 81 and in good health. He doesn’t have any blood in his urine or any other abnormal symptoms. He recently had an X-ray for lower back pain, and the radiologist observed abnormalities that resulted in a CT scan with contrast (oral and IV). The major finding is as follows: “There is an ill-defined soft tissue mass involving the left posterior perirenal retroperitoneum. Neoplastic process is certainly not excluded, and further evaluation is recommended with tissue sampling.”
He has the first consultation with a urologist, and we assume that a biopsy will be scheduled. Our questions are: Should the mass be surgically removed if the tissue is benign? If the mass is malignant (such as a sarcoma), what specialists are needed — a surgical oncologist? If so, what is the treatment and prognosis? Finally, how common are these growths?
D.G.
The retroperitoneum is the space behind the abdominal cavity. The kidneys are retroperitoneal organs, and this mass is right next to the left kidney. The most concerning possibility with this finding is a rare condition called retroperitoneal sarcoma (RPS). It is quite rare, affecting about 2.7 people in a million.
You are quite right that a biopsy is appropriate. The biopsy is usually done by guided imaging. We used to worry that a biopsy would cause the cancer to spread locally, especially with sarcomas, but this happens only rarely, less than 0.5% of the time.
Once your husband has a diagnosis, then I can answer questions about prognosis and treatment. There are “benign” causes, like Castleman disease and retroperitoneal fibrosis, but these are benign only because they aren’t cancer. They are still very serious diseases that have the potential to grow and cause damage that is challenging to treat. There are other tumours, both benign and malignant, some of which (like lymphoma and testicular cancer) are often extremely treatable. If this is RPS, treatment usually includes surgery, radiation and chemotherapy, but knowing the exact type of tumour is necessary before making a plan.
With a diagnosis, your husband’s case would typically be discussed by several experts, including a diagnostic radiologist (to help evaluate whether the tumour can be removed); a pathologist; a surgeon with special expertise in cancer; a radiation oncologist; and a medical oncologist. With several experts in the same room discussing his case, he will get a treatment plan that is unique for his situation. I strongly recommend he be treated in a referral hospital that frequently treats sarcomas and other types of retroperitoneal tumours.
Readers may email questions to [email protected].
