Abstract
In May-Thurner syndrome (MTS), the left iliac vein is compressed by the right iliac artery, leading to restricted blood flow from the leg to the heart. MTS commonly manifests in young females; however, its occurrence in older adults necessitates verifying the possibility of malignancy. A 77-year-old female experienced leg swelling and discomfort for 1 week. Computed tomography angiography suggested extensive thrombosis in the left iliac vein. Despite heparin treatment, the thrombus persisted and required mechanical thrombectomy, balloon venoplasty, and stent placement for tight iliac vein stenosis. The procedure was successful; however a biopsy of thrombus revealed malignant cells. An underlying malignancy and a hypercoagulable state were identified as the contributing factors after further evaluations. This case underscores the importance for vigilant diagnosis of hypercoagulable conditions and malignancies in MTS, emphasizing the role of malignancy in the development of DVT and MTS.