A 26-year-old woman presented with persistent painless swelling of the left thigh of about 6 years duration. The swelling had gradually become more severe. Physical examination revealed a swollen left thigh, which was 6 cm larger in circumference than the right thigh. The patient did not recall any episode of deep venous thrombosis. Findings were normal at bilateral lower extremity venous Doppler ultrasonography (US); abdominopelvic computed tomography (CT) and left iliac venography were performed thereafter.