Wilms Tumors

Diagnosis

Among the most common cancers in children, Nephroblastoma, or Wilms’ Tumor, accounts for 5% of all childhood cancers (American Cancer Society, 2018). The tumor is named after Max Wilms, a German doctor who wrote one of the first medical articles about the disease in 1899. Wilms’ Tumor is the cause nine out of ten cases of kidney cancer in children (American Cancer Society, 2018). Approximately, 500 new cases are found each year in the United States. Diagnosis typically occurs between three and four years of age (American Cancer Society, 2018).

Definition

Wilms’ Tumor is staged based on the extent of tumor spread (Schub &Smith, 2016). In stage one, the tumor is limited to the kidney and can be completely excised (Schub & Smith, 2016).

The tumor extends beyond the kidney, with no peritoneal involvement in stage two. The tumor in stage two can still be completely be excised (Schub & Smith, 2016). Within stage three, no hematogenous via bloodstream metastases, but residual tumor confined to the abdomen remains following a surgery (Schub & Smith, 2016). Hematogenous metastases are present in stage four. By stage five, there is bilateral kidney involvement at the time of diagnosis (Schub & Smith, 2016).
The tumor development is not only staged for diagnosis, it is also separated by type to determine the course of treatment.

There are two major categories of Wilms’ Tumors based on histology being either favorable or unfavorable (American Cancer Society, 2018). A favorable histology refers to those cancer cells within the tumor that have no anaplasia, or poor cellular differentiation (American Cancer Society, 2018). With the rate of favorable histology being around 90%, there is a high chance of cure (American Cancer Society, 2018). The second type of Wilms’ Tumor has a more unfavorable of histology. This tumor hosts cells that vary in appearance. The cell’s nuclei tend to be distorted and enlarged (American Cancer Society, 2018). The more anaplasia a tumor has, the more difficult it is to cure (American Cancer Society,

2018).
Symptoms
The swelling or a hard mass in the abdomen is often the first sign of a Wilms’ tumor (Schub & Smith, 2016). Parents may notice this while bathing or dressing their child. It feels firm and is often large enough to be felt on both sides of the abdomen (Schub & Smith, 2016). Other possible symptoms can be attributed to many other childhood ailments including: fever, nausea, shortness of breath, constipation and blood in the urine (Schub & Smith, 2016). Possible congenital abnormalities or familial history add to physician suspicion and examination (Schub & Smith, 2016).
Causes
Unlike many cancers in adults, childhood cancers are not strongly linked to lifestyle or environmental risk factors.

Childhood cancers are often the result of deoxyribonucleic acid (DNA) changes in cells very early in life, sometimes even before birth (American Cancer Society, 2018). The cause of Wilms’ Tumor has remained virtually unknown to doctors and researchers; nevertheless, they have made great progress in understanding typical and atypical kidney development (American Cancer Society, 2018). The kidneys develop early in the fetal stage of development. Mutations in certain genes in early kidney cells can be problematic during development (American Cancer Society, 2018). Some cells that are to develop fully into mature kidney cells occasionally remain early cells. If the maturation of the cells does not happen, the cells may begin to grow out of control, resulting nephroblastoma (American Cancer Society,

2018).
Several risk factors have been identified as links to Wilms’ Tumor (American Cancer Society, 2018). In the United States, African American children are slightly more at risk than Caucasian and Asian-American children. Girls are also at a slightly higher risk than boys (American Cancer Society, 2018). About 1% to 2% of children with nephroblastoma have one or more relatives, not specifically parents, with the same cancer (American Cancer Society, 2018). Scientists think that these children inherit chromosomes with an abnormal or missing gene from a parent that increases their risk of developing Wilms’ Tumor (American Cancer Society, 2018). About 1 child in 10 with Wilms’ Tumor also has birth defects. Many of these birth defects are caused by chromosomal abnormalities including the WT1, the first Wilms’ Tumor suppressor gene found at chromosomal band 11p13 (Schub & Smith, 2016). This was identified as a direct result of the study of children with Wilms’ Tumor who also had aniridia, genitourinary anomalies, and mental retardation (Schub & Smith, 2016).
Diagnostic Tests and Treatment
It is imperative to detect the tumor in an early stage, as the tumor can become large and metastasize to other organs, especially the lungs (Schub & Smith, 2016). Wilms’ Tumor is often discovered when a parent notices a mass below the costal margin, or at the bottom edge of the rib cage (Schub & Smith, 2016). Imaging studies are then ordered to confirm the presence of a kidney tumor and assess for the presence of distant metastasis (Schub & Smith, 2016). A renal ultrasound will confirm the existence of the kidney mass, with an abdominal ultrasound recommended within twenty-four hours post mass discovery (Schub & Smith, 2016). A biopsy is also performed to confirm diagnosis. Furthermore, a chest x-ray, computerized tomography scan, and other scans of the bone and liver are performed to detect the abnormal mass and if the tumor has metastasized (Schub & Smith, 2016).
Wilms’ Tumor is said to be a “therapeutic success story” in pediatric oncology (Schub & Smith, 2016, p.1). With proper treatment, the prognosis is excellent in patients. Treatment is multimodal, and depends on the tumor’s stage (Schub & Smith, 2016). The standard of treatment for Wilms’ Tumor in stage one and two is to surgically remove the tumor and part of the surrounding kidney tissue, simple nephrectomy to remove the entire kidney, or radical nephrectomy to remove the entire kidney, surrounding tissues, the adrenal gland, and neighboring lymph nodes (Schub & Smith, 2016). Chemotherapy is typical to follow any of these procedures (Schub & Smith, 2016). In cases where the tumor is in stage three and four, the treatment plan is similar with added radiation (Schub & Smith, 2016). Treatment for stage five is removal of both kidneys, in which the patient will require dialysis until a transplant is possible (Schub & Smith, 2016). There is new successful technology being used in isolated cases in stage five where tumor treatment is being done using a harmonic scalpel. This cutting instrument excises and clots tissue using vibration (Schub & Smith, 2016). With current multimodality therapy, approximately 80 to 90% of children with a diagnosis of Wilms’ Tumor, their cancer is cured (Schub & Smith, 2016).
Potential Implications of Development in Preschoolers
Wilms Tumor tends to occur in young children. The average age at diagnosis is three to four years old, becoming less common as children grow older (American Cancer Society, 2018). Wilms Tumor is uncommon after age six and very rare in adults, although cases have been reported (Schub & Smith, 2016).