Nephroblastoma (from the Greek "nephros" - the kidney and "blastoma" - neoplasm) is the most common malignant kidney tumor in children. The tumor is also known as Wilms' tumor after the German surgeon Max Wilms (1867-1918), who first described the disease.

The peak incidence is between the second and third year of life. There are around 100 new cases per year in Germany, with girls being affected slightly more frequently. Bilateral occurrence is observed in 5 % of cases and may be due to a familial tumor disease. There are no specific symptoms of nephroblastoma.

The first symptoms are often a painless increase in the abdominal circumference, but abdominal pain and a palpable mass in the upper abdomen can also occur. Fever, weakness and fatigue often only occur in the late stages of the disease. High blood pressure is rare (10-20% of cases). Blood is also found in the urine in around 5-10% of children.

In Germany, all malignant diseases that occur in childhood are treated according to binding protocols specified by the Society for Pediatric Oncology and Hematology (GPOH) (www.kinderkrebstudien.de). The Department of Pediatric Surgery at Hannover Medical School, together with the Department of Pediatric Hematology and Oncology, is certified by the German Cancer Society as a competence center in pediatric oncology.

For us, this means that all oncology patients are always treated jointly with the Department of Pediatric Oncology and Hematology at the MHH .

This also applies to Wilms' tumor. While in other countries (e.g. in the USA) the tumor is first removed surgically, all children with Wilms' tumors in Germany are treated according to the study protocol of the GPOH or SIOP (Société Internationale d'Oncologie Pédiatrique). This involves 4 weeks of chemotherapy before the tumor is removed. This is usually followed by another course of chemotherapy

If Wilms' tumor is suspected or diagnosed, your child will be examined by a team of pediatric surgeons, pediatric oncologists and radiologists on the day of admission. It is important that we introduce ourselves as a whole team from the first contact with you so that you know what to expect and we can plan the next steps together.

Due to the typical image of the Wilms tumor on ultrasound, the diagnosis is usually made quickly and the second, usually healthy, kidney is also examined. In rare cases, we also need a so-called "sectional image examination" (e.g. magnetic resonance imaging or "MRI"). A tissue sample of the tumor is not usually taken for diagnosis. This is only necessary in exceptional cases, e.g. if your child is either younger than 6 months or older than 16 years and other diagnoses are possible. A possible spread of the tumor to other organs (e.g. lungs) can be examined with a normal chest x-ray.

After these initial examinations have been carried out and we have discussed the rough treatment plan with you, you will first be placed in the care of the pediatric oncologists (oncologist = physician who deals with tumors). The treatment of Wilms' tumor consists of chemotherapy and surgical removal of the tumor and, if necessary (in rare cases), radiotherapy. The exact treatment regimen depends on the spread of the tumor and the tumor structure and follows the guidelines of the treatment studies mentioned above.

An inpatient stay of around 4-7 days must be planned for the surgical removal of the tumor. The inpatient admission takes place one day before the actual operation in order to discuss the upcoming procedure with you in peace and quiet and to carry out final blood tests. During the operation, an incision is made across the abdominal wall. The organs that lie above or near the affected kidney are then carefully pushed aside and the kidney is isolated from all surrounding tissue. The kidney on the other side is also inspected to rule out the presence of a tumor. The aim of the operation is usually to completely remove the tumor together with the affected kidney and the surrounding lymph nodes in order to prevent the tumor from recurring. The removed tumor is then examined under the microscope by a tissue specialist (pathologist).

 

 

The pediatric oncologists will take over the further care of your child after the operation. Thanks to the interdisciplinary cooperation between surgery, oncology and radiotherapy, the current overall survival rate for unilateral nephroblastoma without spread is over 90%. However, the individual risk of individual patients depends on the respective tumor subtype and location and can therefore not be stated in general terms here.