Renal venous thrombosis with calcification and preservation of renal function.

Two neonates were found on US to have branching linear calcification in the renal parenchyma, right sided in one and bilateral in the other. CT confirmed the presence of branching calcification in the kidneys and demonstrated calcified thrombus in the inferior vena cava in both babies. Antenatal detection of adrenal haemorrhage in one baby and presence of calcification at the age of 3 days in the other indicate that thrombosis probably occurred before birth. The kidneys remained normal in size, and uptake of 99mTc-labelled dimercaptosuccinic acid (99mTc-DMSA) was normal on follow-up examination. The presence of branching calcification and normal renal size probably indicates good prognosis for renal function in neonates in whom renal venous thrombosis is found and may indicate prenatal thrombosis.