Wilms Tumor

Original Editors - Students from Bellarmine University's Pathophysiology of Complex Patient Problems project.

Top Contributors - Rachel Flaherty and Allison Hafele 

Introduction

Wilms tumour is a malignant paediatric renal tumour. Also known as nephroblastoma.

                                          

Epidemiology

Wilms tumours are the most common paediatric renal mass (reportedly 85% of cases) and 7% of all childhood cancers are Wilms tumours. They are most common in children ages 3 to 4 and becomes much less common after the age of 5. Wilms’ tumor affects boys and girls equally, and can also be found in adults, though it is very rare.

Characteristics/Clinical Presentation

Wilms’ tumor is often hard to find early because the tumor can grow large without any signs or symptoms. These children may look and act normally. The most common first clinical sign is swelling or a hard mass in the abdomen. It is often firm and large enough to be palpated on both sides of the abdomen, and is usually not painful. Haematuria occurs in ~20% of cases. Hypertension, due to excessive renin production, is found in up to 1/4 of patients. Acquired von Willebrand disease occurs in 8% of cases.

Diagnosis

Diagnosis includes:

• A physical exam looking for possible signs of Wilms' tumor.
• Blood and urine tests to see how the kidneys are working.
• Imaging tests may include an ultrasound, computerized tomography (CT) or magnetic resonance imaging (MRI).

Etiology/Causes

Wilms’ tumor is typically seen in otherwise healthy children, and the exact cause in most children is unknown. However, approximately 10% of patients with the tumor have a congenital anomaly, including certain birth defect syndromes and genetic changes. Wilms’ tumor, whether hereditary or sporadic, shows evidence of changes in one or more of at least ten different genes.
Kidneys are developed early in fetal growth. Gene mutations in early kidney cells may lead to undeveloped immature kidney cells. These early kidney cells may remain after birth. If the cells do not mature, they may grow out of proportion, forming a Wilms’ tumor. Genes WT1 and WT2 on chromosome 11 are tumor suppressor genes, and mutations of these cause a small number of Wilms’ tumors.
Common syndromes that are associated with Wilms’ tumor include the following:
WAGR Syndrome: WAGR stands for Wilms tumor, Aniridia (lack of the iris of the eyes), Genitourinary tract abnormalities, and mental retardation. Children who have WAGR syndrome have approximately 30-50% chance of developing a Wilms’ tumor, and often have them bilaterally. In this syndrome, cells are missing part of chromosome 11, which involves the WT1 gene.
Beckwith-Wiedemann sydrome: These children are at a 5% risk of having a Wilms’ tumor. This syndrome is caused by a malformation of chromosome 11.
Denys-Drash Syndrome: This syndrome is also caused by mutations to the WT1 gene. The risk for Wilms’ tumor in these patients is greater than 90%. In this disease, the kidneys become diseased and no longer function at a very young age, leading to a Wilms’ tumor.                               

Medical Management

Management of Wilms’ tumor involves surgery, chemotherapy, and radiation therapy. Most children will receive more than one type of treatment. Treatment is based on both the stage and histology of the Wilms’ tumor.

• Unilateral Wilms tumours are, usually, treated by a combination of nephrectomy and chemotherapy.
• Radiotherapy has a small role, but may be used if peritoneal spread or incomplete resection occurs.

Cure today is possible ~90% of the time. Recurrence can occurs within the tumour area, or distally within the lungs or liver.   

Physical Therapy Management

There are several long-term side effects of chemotherapy. Childhood cancers tend to respond better to chemotherapy than adult cancers. Children’s bodies also tend to tolerate it better than adults do.  Side effects of chemotherapy can include fatigue or extreme tiredness from having too few red blood cells.

Musculoskeletal complications that can occur due to radiation therapy include growth abnormalities and hypoplasia. Mild scoliosis and mild asymmetry of all musculoskeletal structures can occur due to reduced growth of bone and paravertebral muscles. These effects are more pronounced the younger the patient is at the time of radiation therapy. 

Physical therapy interventions may include strengthening postural muscles and also increasing endurance to promote a higher quality of life. Patients should avoid heavy lifting due to the decreased bone density and risk of osteoporosis.

Alternative/Holistic Management

Complementary medicine is treatment used in combination with regular medical care. Alternative treatments are used instead of the traditional medical treatment. Although there are not any alternative medicines to surgery, radiation or chemotherapy, there are complementary treatments including art therapy or play therapy to reduce stress, peppermint tea to relieve nausea, and acupuncture to help relieve pain.  See Resources for a link to healthy living after treatment for childhood cancer

Differential Diagnosis

• - Clear cell sarcoma  

• - Malignant rhaboid tumor  
• - Autosomal recessive polycystic kidney disease (ARPKD)
• - Autosomal dominant polycystic kidney disease (ADPKD)
• - Hydronephrosis
• - Renal carbuncles
• - Hemorrhage
• - Neuroblastoma, an embryonal malignancy of the adrenal gland, usually affect the same age group and commonly arise in the same general region of the abdomen 

Case Reports/ Case Studies

add links to case studies here (case studies should be added on new pages using the case study template)

WT1 mutation as a cause of 46 XY DSD and Wilm's tumour a case report and literature review

A Report of Three Cases Cured of Pumonary and Hepatic Metastases

Wilms' Tumor Metastatic to Bilateral Testes at Presentation Case and Review of the Literature

Extrarenal Wilms' Tumor of the Ovary- A Case Report and Short Review of the Literature