Understanding Wilms

Wilms' tumor or nephroblastoma is a malignant cancer arising in the kidney that usually occurs in your children, occasionally in children over 5 and very rarely in adults.  Its common name is an eponym, referring to Dr. Max Wilms, ther German surgeon (1867-1918) who first decribed the tumor.

Approximately 100 cases are diagnosed in the UK annually.  The majority (75%) occur in otherwise normal children; a minority (25%) are associated with other developmental abnormalities.  Wilms is generally very responsive to chemotherapy, which combined with radiotherapy and surgery results in about 90% of patients surviving at least five years.

Under the microscope, the most commonly observed type is triphasic Wilms and this comprises three types of cells arranged in clusters:

Blastemal cells, Mesenchymal or stromal cells, Epithelial cells.

The Epithelial cells resemble the development of the tubules and glomeruli of the normal kidney and are surrounded by a spindled cell stroma.  The stroma may include striated muscel, cartilage, bone, fat tissue, fibrous tissue.  The tumour causes compression of the normal surrounding kidney. This often causes the blood pressure to be raised at diagnosis and also means that surgical removal of the whole affected kidney forms part of standard treatment.

About 10% of patients have metastatic disease (stage 4 disease) in which Wilms tumour cells are detected at distant sites of the body, usually in the lungs.  Another 10% approximately, have disease arising in both kidneys (termed stage 5).  Stage 5 often has a better prognosis than stage 4 but the surgery often requires conservation of some normal kidney to avoid the patient developing later chronic renal failure and the need for dialysis.

This information was provided by:

John Andersen

Senior Lecturer in Paediatric Oncology

Honorary Consultant Paediatric Oncolgist

Institute of Child Health and Great Ormond Street Hospital