The Fatty Dilemma: A Rare Instance of Extra- and Intravascular Lipoma of the Brachiocephalic Vein.

Oftentimes, incidental findings are made on routine diagnostic imaging. An intra- and extravascular lipoma is one example of an important incidental finding. Intravascular lipomas are rare benign vascular tumors that are typically asymptomatic. They are most commonly found in the inferior vena cava but have also been recorded in the superior vena cava, brachiocephalic vein, subclavian vein, internal jugular vein, external jugular vein, and common femoral vein. Here, we presented the case of a 64-year-old female patient with an incidentally discovered intra- and extravascular lipoma affecting the right subclavian and brachiocephalic veins. While benign, intravascular lipoma on imaging can resemble a malignant tumor such as leiomyosarcoma or thrombus. As a result, appropriate identification and classification of this imaging finding is crucial for avoiding an exorbitant and futile workup.