Renal Cell Carcinoma with a Catastrophic Thrombus: A Case Report.

Introduction: Renal cell carcinoma (RCC) is a common malignancy known for its potential to invade the venous system, particularly the inferior vena cava (IVC), leading to tumor thrombus (TT) formation. While the presence of TT in RCC isn't unique, extension of TT above the diaphragm is rare. This case highlights the challenges encountered in diagnosing and managing RCC with extensive TT involvement.

Case report: A 69-year-old man presents with 3-month history of dyspnea and increasing fatigue in the setting of 30 pounds weight loss. Laboratory studies showed anemia and acute kidney injury. CT abdomen and pelvis revealed 6.8cm solid mass within the left perinephric space, enlarged IVC with large thrombus. Kidney biopsy returned positive for clear cell renal carcinoma with metastasis to the liver. Several days into the hospitalization the patient began to experience increased abdominal pain. Repeat ultrasound showed tumor thrombus with extension within the intrahepatic IVC and hepatic veins and reversal of portal venous flow. During the imaging study, the patient suffered a cardiac arrest and expired. Postmortem examination revealed diffuse showering of tumor emboli within the pulmonary arteries, likely contributing to the patient's rapidly progressive respiratory failure, and subsequent cardiovascular collapse.

Conclusion: This case illustrates the complexity of treating patients with extensive TT. In patients with RCC associated TT, the risk for thromboembolism is increased substantially, however the full benefit of anticoagulation remains controversial. Understanding the intricacies of TT involvement and its potential complications is crucial in guiding treatment decisions in patients with significant tumor thrombus burden.