A rare case of inferior vena cava agenesis associated with deep venous thrombosis

Inferior vena cava (IVC) agenesis is an extremely rare malformation, most times diagnosed randomly, representing an important risk factor in the development of spontaneous deep venous thrombosis (DVT) in children and young adults. We present the case of an 8-year-old male child admitted in our clinic for the following complains: right lumbar pain with paravertebral irradiation. The personal pathological history revealed a recent appendectomy. At the time of admission, an abdominal ultrasound was performed which revealed right nephromegaly, and also raised the suspicion of IVC agenesis. We performed a thoraco-abdominal angio-CT exam with contrast enhancement which confirmed the diagnosis of IVC agenesis and right common iliac vein, venous thrombosis of the right external iliac vein, right common femoral vein and right superficial femoral vein. We excluded a potential antiphospholipid syndrome or a thrombophilia, and the genetic tests ruled out the possibility of a family predisposition. We initiated anticoagulant therapy with close monitoring of the coagulation parameters, the evolution being favorable. Despite the very low frequency of this malformation, the early and correct diagnosis is essential for these patients’ management and prognosis.