Wilms' tumour (nephroblastoma) is one of the most common solid maligna
nt tumours in infancy and childhood. In about 40% of cases, invasion o
f the renal vein is present. Rarely, these tumours extend into the inf
erior vena cava and right atrium. We discuss a 7-week-old girl who pre
sented with acute massive pulmonary embolism, and was found to have a
large tumour of the left kidney. Later on, the diagnosis of Wilms' tum
our was confirmed. Wilms' tumour presenting as massive pulmonary embol
ism is extremely rare; to our knowledge this is the fourth case descri
bed in literature. We review the cases previously described, and comme
nt on the diagnostic and therapeutic features of this clinical entity.