A 22–year–old Caucasian gentleman was referred for the evaluation of a 5–day history of non traumatic lower backache and fever. Backache was acute in onset, non radiating, dull in character and of 4/10 in intensity. The pain increased with raising the lower extremities in supine position. Fever was low grade and associated with night sweats. He was a nonsmoker with no other co–morbidities. Physical examination revealed mild tenderness in the lower para–spinal region without any neurological deficits. Laboratory data was unremarkable except white blood count (WBC) of 11,100/mL, C–reactive protein (CRP) of 177 mg/L and erythrocyte sedimentation rate (ESR) of 53 mm/h. Radiological investigations were unremarkable for any abscess or lymphadenopathy but a striking finding was an interrupted inferior vena cava and multiple collaterals draining into supra hepatic circulation on CT abdomen with contrast. MRI abdomen/pelvis with contrast revealed thrombosis in the inferior vena cava and common iliac veins. Widespread inflammatory changes surrounding these venous structures were compatible with acute thrombophlebitis. The patient was started on anticoagulation with subcutaneous enoxaparin. He was not given any antibiotics and his urine and blood cultures remained negative. His symptoms resolved on anticoagulation and he was discharged on warfarin.
Absent inferior vena cava is a rare anomaly, 0.3% of otherwise healthy individuals. It is associated with idiopathic deep venous thrombosis, particularly in the young. Review of the literature revealed that fever along with elevated inflammatory markers (WBC, ESR, and CRP) is a common presentation. Computed tomography or preferably magnetic resonance imaging, are required to delineate inferior vena cava anatomy and ascertain proximal extent of the thrombus. Although invasive therapeutic modalities exist, long–term and commonly life–long anticoagulation is often required.
This case highlights the importance of keeping noninfectious etiologies in mind while investigating fever, and backache with elevated inflammatory markers.
Figure 1CT abdomen with contrast showing interrupted inferior vena cava and collaterals.