Pulmonary embolism secondary to renal tumor thrombus embolization: a challenging scenario

Pulmonary embolism (PE) may reveal an occult malignancy or complicate the course of an existing cancer. Renal cell carcinoma (RCC) is highly thrombogenic, especially in the presence of venous extension or tumor thrombus into the renal vein or inferior vena cava. However, PE as a presenting or associated event of RCC is relatively uncommon and may mislead initial diagnostic orientation. We report the case of a 55-year-old North African man presenting with acute dyspnea and pleuritic chest pain in whom computed tomographic pulmonary angiography confirmed segmental bilateral pulmonary emboli. Lower limb Doppler ultrasound was negative for deep venous thrombosis. Abdominal imaging subsequently revealed a large right renal mass with invasion of the renal vein, consistent with renal cell carcinoma with tumor thrombus. Anticoagulation was initiated, and a multidisciplinary discussion led to a plan for radical nephrectomy with thrombectomy. While urgent surgical management (radical nephrectomy + IVC thrombectomy) was being discussed with vascular surgery and anesthesia, the patient experienced abrupt cardiovascular collapse and died. Histological confirmation could not be obtained. The final diagnosis was: suspected clear cell RCC with Mayo III venous extension complicated by bilateral segmental pulmonary embolism. This case illustrates that PE may be the initial manifestation of RCC. In cancer-associated thrombosis, absence of lower-limb deep vein thrombosis (DVT) should raise suspicion of an atypical source such as visceral venous tumor thrombus. Early imaging of the abdomen, particularly the renal–caval axis, can be crucial. Management requires coordination between oncology, urology, and vascular teams, balancing thrombotic and bleeding risks.