An unexpected recurrence of rectal squamous cell cancer presenting as deep vein thrombosis

Tumor thrombus is an uncommon oncologic complication and is exceedingly rare in the setting of colorectal cancer. We present the case of a 71-year-old woman with a significant oncologic history, including rectal squamous cell cancer, who presented with left lower extremity deep vein thrombosis. She underwent left lower extremity venography and thrombectomy of the left common iliac vein. Pathologic examination revealed fragments of squamous cell carcinoma embedded in an organizing thrombus. A covered stent was placed in the common iliac vein across the internal iliac vein origin. Positron emission tomography-computed tomography confirmed mediastinal and retroperitoneal lymphadenopathy, which was managed with adjuvant carboplatin and paclitaxel chemotherapy.