'What IVC?': Deep Vein Thrombosis in the Context of IVC Dysgenesis

Among young, otherwise healthy adults with unprovoked deep vein thrombosis (DVT), uncommon causes like variation in the normal sequential development of the inferior vena cava (IVC), must be explored. Anomalous IVC conditions are estimated to occur in up to 9% of the general population, with the rarest anomaly being IVC agenesis at 0.0005% - 1% general population prevalence. DVTs are more likely to develop in this population due to venous stasis from decreased venous return, even with the formation of extensive collateral veins. Herein, the authorial team presents a 22-year-old patient with leg pain and swelling who was found to have acute DVT, and, incidentally, the absence of the suprarenal IVC with a robust collateral system on further imaging studies. The morbidity of DVTs in this population is very high, and attention should be given to young patients who present with new-onset DVT in the setting of normal coagulation studies and lack of personal or family history of clotting disorders, as the need for specialized imaging such as venograms is necessary to secure the proper diagnosis.