Servier – Phlebolymphology

Deep vein thrombosis (DVT) is a common diagnosis in the emergency department (ED). It’s fundamental to be aware of its differential diagnosis, as different pathologies present with similar symptoms. The current study reports on a rare case of adventitial cystic disease (ACD) involving the femoral vein.

A 45-year-old female patient comes to the ED due to edema of the left lower limb for about 5 months. She was anticoagulated with rivaroxaban for a probably misdiagnosed femoral DVT. There was a clear asymmetric swelling of the left lower limb. Doppler ultrasound (DUS) showed an encapsulated hypoechoic mass protruding to the wall of the femoral vein, leading to abnormal blood drainage. Computed tomography angiography (CTA) confirmed a hypodense, well-defined mass having a compressive effect on the femoral vein. Surgical exploration identified a cystic structure in continuity with the femoral vein’s wall. Lesion resection was performed, and reconstruction of the vein wall was done. Histological examination confirmed that the mass was a venous cyst.

ACD of the venous system is rare, with few cases described in literature. Diagnosis can be suspected through clinical and imaging findings; however, it’s often made during or after surgery. The first imaging method should probably be DUS due to its availability, low cost, and absence of radiation. Computed tomography seems to be an adequate method for the evaluation of this pathology as it can help in the surgical strategy and allows the percutaneous drainage of the lesion. Given the small number of cases described, ideal treatment is still unknown, but most authors advocate resection of the cyst and its wall to prevent recurrence. Venous ACD is rare, but it should be suspected in patients with symptoms of DVT, especially when the diagnostic investigation indicates an extrinsic mass. Close follow-up is necessary to prevent recurrence.