This report describes an autopsied case of inferior vena caval thrombosis that occurred secondary to blunt trauma in a 21-year-old man. Fourteen days after the injury, he died of massive thromboembolism of the main pulmonary artery. Implications of this case and a review of the literature are presented.

An 81-year-old Japanese man, who complained of right orbital pain and reduced right visual acuity to the level of light perception, was admitted to our hospital. He had a history of sustained atrial fibrillation and took dabigatran (220 mg/day).The blood laboratory data showed a mild inflammatory reaction, and the cerebrospinal fluid examination was essentially normal.The whole-body computed tomography (CT) showed no findings suggestive of a malignancy. Cerebral magnetic resonance imaging (MRI) with intravenous gadolinium administration showed marked enhancement of the bilateral cavernous sinuses and right orbital apex area (Figure 1A). A transorbital biopsy of the lesion was scheduled to confirm the pathological diagnosis. Four days before the biopsy, dabigatran was changed to unfractionated heparin. Dabigatran administration was immediately resumed after the biopsy. The biopsy specimen revealed nonspecific inflammatory cell infiltration.A definitive diagnosis was not achieved, but an idiopathic autoimmune reaction was suspected. After initiating steroid treatment, the patient's right orbital pain and abnormal imaging findings were resolved, but he remained blind in the right eye.On the 13th hospital day, a follow-up cerebral MRI revealed an asymptomatic cerebellar infarction (Figure 1B). On the 41st hospital day, a repeat cerebral MRI showed another small asymptomatic cerebral infarction in the right occipital lobe (Figure 1C). Chest CT and transesophageal echocardiography revealed an asymptomatic hillshaped pulmonary artery thrombus (Figure 1D) and a free-floating ball-shaped left atrial thrombus (Figure 1E). Dabigatran was changed to rivaroxaban (30 mg/day), but the intracardiac thrombus persisted.Therefore, the patient underwent a left atrial appendectomy for thrombus removal on the 61st hospital day (Figure 1F). Heparin-induced thrombocytopenia (HIT) was suspected because of the significant decline in platelet counts after heparin administration and the presence of multiple thromboses (Figure 1G).