Congenital interruption of the inferior vena cava is an uncommon vascular a
nomaly. In this setting, the appearance of deep vein thrombosis is very rar
e because associated azygous or portal continuation develops as a collatera
l system for venous return. The authors present a case of infrahepatic inte
rruption of the inferior vena cava in a 21-year-old man who presented with
symptoms of deep vein thrombosis. Clinical features and prognosis of this e
ntity are discussed.