Wilms' tumour in infancy.

During a 15-y period, 48 children were treated for Wilms' tumour (WT). Seven of them were < 1 y of age at diagnosis. One child presented with non-traumatic haematuria, but in all the other children WT was revealed as a palpable abdominal mass at routine examination or investigation due to another disease. The four children under 6 months of age at diagnosis were primarily operated upon; the others received preoperative chemotherapy. Two children had chromosomal aberrations in the WT tumour specimen. The follow-up revealed that postoperatively six children are healthy with no evidence of relapse from WT, but one child had a contralateral relapse successfully enucleated. The clinical behaviour and management of WT in infants differ compared with that in older children. The diagnosis may be uncertain and it can be difficult to distinguish between malignant and non-malignant lesions. It is essential to realize the possibility of WT, even in children < 1 y of age.