What is Wilms' Tumor?

Wilms' tumor, also known as nephroblastoma, is a tumor that develops from embryonal kidney remnants in the kidney. With early diagnosis and treatment, 95% of Wilms' tumor patients can completely recover from the disease.

What is the Frequency of Wilms' Tumor?

Wilms' tumor is a rare type of kidney cancer that affects young children. It is usually seen between the ages of 2-5 and approximately 150-200 cases are seen annually in our country. Wilms' tumor is the most common kidney tumor seen in children. While approximately 95% of the tumor is seen in a single kidney, both kidneys are affected when diagnosed in 5%.

It constitutes 6% of all childhood cancers. It is seen equally in girls and boys. Three-quarters of the cases are diagnosed between the ages of 1-8. The average age of diagnosis is under 3 years old.

Are There Risk Factors That Cause Wilms' Tumor?

The exact cause of Wilms' tumor is unknown. However, there are some defined risk factors.

Sometimes it has a familial characteristic and genetic disorders are detected in those families. There are also some chromosomal anomalies defined in the tumor.

Are There Any Diseases Accompanying Wilms' Tumor?

In unilateral cases, there is an additional anomaly in 10% and in bilateral cases, there is an additional anomaly in approximately 70%. The disease may be accompanied by some hereditary disorders (WAGR Syndrome, Denys-Drash Syndrome, BeckwithWiedemann Syndrome) such as congenital structural disorders such as undescended testicle, horseshoe kidney, absence of the colored layer of the eye (aniridia), enlargement of one half of the body (hemihypertrophy) or one limb (e.g. macroglossia).

 

What are the Clinical Findings of Wilms’ Tumor?

Sick children are usually healthy-looking children. It is usually detected as an asymptomatic mass by the mother during bath time or by the physician during routine examinations, and this group constitutes approximately 90% of the cases.

The most common clinical symptom is a mass in the abdomen. The mass is often hard, painless and smooth. The mass can be large enough to fill the entire abdominal cavity.

 

In addition, less frequently, abdominal pain, fever, constipation, nausea, vomiting, loss of appetite and weight loss may accompany this. Sometimes bleeding is seen in the urine. Rarely, high blood pressure is detected.

Another feature of this tumor is that it forms clots and throws them into the heart and large veins. Due to this, varicocele or heart failure may develop in boys and children with these clinical findings should be careful in terms of Wilms tumor.

How is Wilms' Tumor Diagnosed?

Diagnosis is made by history and physical examination. The clinical findings mentioned above should be taken into consideration in the history. In physical examination; A large, hard, well-circumscribed, painless mass that often fills the entire abdomen is detected. In advanced cases, liver and spleen enlargement, ascites, hypertension may be seen. Heart failure findings and varicocele may be seen in boys. In addition, many of the diseases mentioned above may be seen. Diagnosis is confirmed by blood tests and imaging methods. Unfortunately, there is no blood test that can be used as a definitive diagnosis and follow-up parameter for this tumor. Therefore, imaging methods are mostly used in diagnosis and treatment. Direct X-ray films (line-shaped calcifications can be seen), abdominal ultrasound, imaging methods such as computerized tomography (CT) or magnetic resonance (MR), urine and blood tests are followed by a biopsy for diagnosis.

Is There a Staging for Wilms’ Tumor?

Yes, there is.

• E-I: Tumor localized to kidney, kidney capsule intact, Tumor completely removed
• E-IIA: Kidney capsule involved, renal pelvic vessels involved, or fine needle biopsy performed, Tumor completely removed
• E-IIB: IIA, and regional lymph node spread, Patients who underwent trucut biopsy, Tumor completely removed
• E-III: Para-aortic and pelvic lymph nodes involved, Vava Cava Thrombus present, Tumor cannot be completely removed, remains residual or patients who underwent open biopsy.
• E-IV: Distant metastasis present, lung, liver and bone etc.
• E-V: Bilateral kidney tumor present. In this case, both kidneys are staged separately according to the above criteria.

 

Does Wilms’ Tumor Spread to Neighboring and Distant Organs, That is, Does It Metastasize?

Yes, it can spread. It is a tumor known for metastasis, especially to the lungs and bones. Therefore, the lungs should be evaluated for metastasis before treatment. Lung tomography is used to examine the condition of the lungs, and bone scintigraphy is used to examine spread to the bones.

 

How is Wilms' Tumor Treated?

The basic approach to treating the tumor is surgical removal of the tumor. Since the tumor is well-circumscribed, it is usually completely removed, no matter how large it is. In some cases, if the tumor is very large, chemotherapy (drug therapy) is given after a preliminary diagnosis is made with imaging, and the tumor is removed surgically after it shrinks and a diagnosis is made.

The general approach to treatment is to remove the kidney along with the tumor after evaluating the other kidney.

After the tumor is removed, chemotherapy and/or radiotherapy (radiation therapy) are applied to the surrounding area according to its histopathological condition. The tumor is sensitive to both treatments. Radiotherapy is also added to the treatment in poorly structured tumors or advanced tumors.

Does Wilms' Tumor Recur?

It may recur. If the disease recurs (in cases of relapse), the given treatments can be evaluated and new drug treatments, additional dose radiotherapy and surgery can be used.

What is the Prognosis of Wilms' Tumor?

Nowadays, if diagnosed and treated in time, the prognosis is very good, the survival rate is around 95%. However, the recurrence of the tumor in the same area or its spread to other organs, especially the lungs, during or after treatment (metastasis) indicates that the prognosis is poor.

What are the Complications of Wilms' Tumor Surgery?

Since the surgery will be performed under general anesthesia, there may be some complications related to it, and there are also complications of surgery.

Complications related to Open Surgery:

• Bleeding and abscess development may occur after the surgery. For these reasons, re-surgical intervention or skin interventions may be required.
• Rarely, other intra-abdominal organs are at risk of injury. If such an injury occurs, it is usually repaired during the surgery. Anastomosis leakage may occur after the surgery and a re-operation may be required, and if anastomosis is not possible during the surgery, a colostomy or ileostomy (having the stool placed in a bag connected to the abdomen) may be opened.
• The risk of Incisional Hernia (Incisional hernia) formation in the surgery area is 0.1-1%.
• There may be a long-lasting decrease in sensation and tingling around the surgical area, sometimes permanent.

Adhesion in the intestines (Brid ileus): Adhesions may form between the intestines even years after surgery. Treatment is primarily surgical if there is no medical improvement.

Complications after Wilm's tumor surgery;

• Relapse of the disease
• Organ losses due to bleeding or vascular involvement
• Nerve damage and related functional losses depending on the region of the tumor
• Missing bilateral tumors if the contralateral kidney is not examined

***The information provided here, the content of the website, is arranged for the purpose of informing visitors, especially families. No information should be considered as advice by visitors and should not lead to any decision or action. The patient should definitely have a pediatric surgeon examine the subject, consult with him and make a decision by consulting his/her personal knowledge.