Intravascular Lipoma of the Left Jugular Subclavian Vein Confluence

Objectives: Lipomas are benign, well-circumscribed tumors of welldifferentiated adipocytes.Although they are the most common soft-tissue tumor in adults, their occurrence within the venous system is rare.Many are found incidentally, with inferior vena cava (IVC) lipomas found in 0.5% of the population during contrast-enhanced CT.Some patients however, may present with symptoms of venous compression or deep vein thrombosis (DVT).Although the most common site for venous lipomas is the IVC, these tumors have also been reported in the internal jugular vein (IJV), brachiocephalic vein, innominate vein, renal vein, common femoral vein, and external iliac vein.We report a case of surgical management of intravascular (IV) lipoma found at the confluence of the left IJV and subclavian vein.Methods: Retrospective chart review identified one patient diagnosed and treated for an IV lipoma at the left jugular-subclavian vein confluence in December 2023.Demographic data, preoperative diagnoses, clinical symptoms, and imaging findings were collected.Results: A 58-year-old male with no significant medical history presented after an incidental finding of a 2.0 1.7 1.4 cm mass at the junction of the left subclavian and IJV.The patient denied arm swelling but reported neck discomfort when turning his head left.Ultrasound revealed a non-vascularized homogeneous mass in the area of the left innominate vein.A venogram was then performed to evaluate venous compression and determine whether the mass was intraluminal or extraluminal.Imaging revealed an intraluminal mass causing flow obstruction in the subclavian vein, near-complete effacement of the IJV (Fig, A), and extensive collateral formation.After interdisciplinary discussion, a PET CT-scan was ordered, which confirmed the lesion's benign nature.Based on these findings, surgical excision was recommended.Infraclavicular and supraclavicular incisions were made to access and mobilize the subclavian and jugular veins.The mass was seen to erode into the junction, extending into the left brachiocephalic vein.After clamping the subclavian, jugular, and innominate veins, a venotomy was performed at the junction, allowing complete externalization and removal of the mass with its capsule intact (Fig, B).Postoperatively, the patient developed a chyle leak, which resolved.Two months later, he was diagnosed with a left subclavian DVT, which was treated with anticoagulation.At his 4-month follow-up visit, ultrasound showed no evidence of DVT with patent left IJV, subclavian, brachial, and superficial veins.Conclusions: Intravascular benign venous lipomas are rare occurrences that go unreported unless found incidentally.To the best of our knowledge, this is the first report of an IV lipoma found in the left jugular-subclavian vein confluence.