A True Thrombosed External Jugular Vein Aneurysm Presenting as a Cervical Mass: A Case Report and Literature Review

External jugular venous aneurysms are a rare clinical occurrence. Clinical symptoms such as painless neck swelling that worsens with the Valsalva maneuver, coughing, or straining may point to the diagnosis. Doppler ultrasonography is frequently used to confirm the diagnosis. We report a case of a 43-year-old woman who presented with a one-year history of painless right supraclavicular swelling. She noticed the swelling increases in size with the Valsalva maneuver. Neck ultrasound with color Doppler revealed a vascular structure containing turbulent blood flow; it measured 2.9 x 1.2 cm and appeared partially thrombosed. During further evaluation at our hospital, the patient underwent a computed tomography scan of the neck with intravenous contrast, which revealed a right supraclavicular mass measuring 2.3 x 3.5 cm and likely representing an external jugular vein saccular aneurysm. The patient underwent surgical excision. Histopathological examination of the external jugular vein aneurysm revealed vascular tissue with blood clots, hemosiderin-laden macrophages, and attached benign fibroadipose tissue. The postoperative recovery was uneventful, and the patient was discharged home with regular follow-up in the last one year in our outpatient clinic. Venous aneurysms are an uncommon clinical phenomenon. Saccular venous aneurysms, which mostly affect adults and involve the external jugular venous and internal jugular vein, have degenerative histology and are more prone to thrombosis. Asymptomatic and uncomplicated jugular venous aneurysms should be treated conservatively with regular follow-up. Enlarging, disfiguring, symptomatic, and complicated jugular venous aneurysms, on the other hand, almost always necessitate surgical exclusion and bypass. In comparison to arterial aneurysms, true venous aneurysms are relatively uncommon. For saccular jugular venous aneurysms, surgical excision is the gold standard and is indicated to reduce the risk of aneurysmal rupture and pulmonary embolism.