Kidney Tumors

A variety of tumors make up the spectrum of childhood kidney cancers. Tumors of the kidney are often not diagnosed until they are fairly large and cause pain or swelling. They may spread to the lungs, liver or nearby lymph nodes. Kidney tumors are typically unilateral (only in one kidney), but can be found bilaterally (occurring in both kidneys). Wilms tumor is the most common, making up about 8 percent of all childhood cancers.

Typical symptoms of tumors of the kidney are pain, swelling or a lump in the abdomen and blood in the urine. If a kidney tumor is found wholly contained within one kidney, the typical surgery is a nephrectomy—removal of the entire kidney. If the tumor has spread outside the kidney or is bilateral, portions will be removed.

There are several kinds of kidney tumors:

  • Wilms Tumor is the most common of all kidney tumors, and of all childhood cancers. In fact, Wilms Tumors are generally found before or around 3 years of age. Thye are rarely found after the age of 6. It is slightly more common in females and African Americans.
  • Clear Cell Sarcoma is the second most common type of kidney tumor in children. Clear Cell Sarcoma spreads differently than Wilms Tumor and may be found outside the kidney. It also appears to have a higher relapse rate.
  • Rhabdoid Tumors of the Kidney are generally found in very young children, typically under the age of 2. Rhabdoid tumors have a very rate of spreading.
  • Neuroepithelial Tumors are generally found in young adults and are known to metastasize (spread) quickly.
  • Renal Cell Carcinoma is a kidney tumor that rarely occurs in children, but can spread quickly to lymph nodes, lungs and bones. Renal cell carcinoma may be associated with existing conditions such as Von Hippel-Lindau Disease, tuberous sclerosis, neuroblastoma and/or sickle cell disease.
  • Mesoblastic Nephroma is typically diagnosed in the first three months, sometimes even via an in utero ultrasound. It seems to occur more frequently in males than females.

Many factors affect recovery rate and treatment options:

  • Size and removal of tumor
    Tumors that can be completely removed (resected) by a surgical treatment have a higher recovery rate. Chemotherapy may also be used to shrink the tumor for removal or to reach cancerous cells in other parts of the body. Generally, Wilms Tumors are more contained than other kinds of kidney tumors.
  • Stage of tumor
    As with many cancers, Stage I and II tumors are more easily cured. The earlier the tumor is detected, the better chance for removal and treatment.
  • Type of tumor
    Certain types of kidney tumors have better recovery rates.
  • Favorable Histology
    The histology of a tumor, or the condition of its cells as seen under a microscope, affects the recovery rate. A Wilms Tumor with no anaplasia (cells with bizarre edges and shapes) has a 95 percent chance of full recovery. Additionally, some of the kidney tumors, such as Wilms and renal cell carcinoma, appear to have some genetic connections. Tumors with abnormal chromosomes or genes may be more difficult to treat.