A Case of Mistaken Identity: When a Deep Vein Thrombosis is not a Thrombosis

Abstract

Introduction Although rare, nonthrombotic causes of venous obstruction do occur. Their ultrasound findings can mimic deep vein thrombosis (DVT). We sought to examine the ultrasound appearance of these tumors to determine whether their differentiation from DVT was possible. Case Report Two patients, in whom a DVT was initially suspected, were subsequently diagnosed with intravascular tumors: a leiomyosarcoma and a hemangioma. The first patient presented with thigh pain, and an initial diagnosis of long saphenous vein (LSV) and common femoral vein thrombosis was made. The apparent thrombus remained unchanged despite anticoagulation. Proliferation of the lesion outside of the LSV developed, resulting in a review of the diagnosis, and surgical resection was performed. A histological diagnosis of leiomyosarcoma was made. The second patient presented with leg swelling and an initial diagnosis of External Iliac vein thrombosis was made. Further ultrasound assessments demonstrated arterialized flow within the lesion and surgical resection was performed, with a histological diagnosis of intravascular epithelioid hemangioma. Results The B-mode appearance was similar for both. The presence of arterialized flow within the lesions is helpful but may not be diagnostic because of recent reports that neovascularization may develop within thrombus. Conclusion Suspicion needs to be raised in a patient presenting with an unprovoked DVT or when conventional treatment does not result in improvement of symptoms; as well as when prolonged arterialization is identified within the thrombus. These signs can alert the clinician to a possible non-thrombotic mechanism of venous obstruction.