Background Venous thrombosis (VT) in children is increasingly diagnosed and treated because of better imagistic and genetic diagnostic possibilities.

Case report A 16-year-old male child without any significant medical history was referred to our clinic with suspicion of deep vein thrombosis. He accused left inguinal pain which irradiated in the left limb associated with local oedema and cough. Doppler echography confirmed thrombosis of left common femoral vein, left vena saphena to vena popliteal level. We completed the imagistic investigations with abdominal angio – CT which show a complex inferior vena cava malformation: duplication of inferior vena cava and lack of infrarenal inferior vena cava segment. Pulmonary CT excluded pulmonary embolism.

To determine the underlying risk factors of the extended thrombosis thrombophilia factors were evaluated and many of them could be incriminated. The patient has multiple genetic factors for thrombofilia. Lupus anticoagulant was detected also so we will follow up the patient for suspicion of antiphospholipidic syndrome.

Anticoagulant treatment was initiated and patient is continues follow up.