Immuno-oncology therapy associated thromboembolic events in metastatic renal cell carcinoma.

The relationship between thromboembolic events (TEs) and immune-oncology (IO) agents in patients with metastatic renal cell carcinoma (mRCC) with inferior-vena-cava (IVC) thrombus has not been explored despite conferring significant morbidity. A late 30s female is diagnosed with mRCC with a level-II IVC thrombus after presenting with back pain. Two weeks post initiation of immunotherapy, she re-presented with bilateral sub-massive pulmonary emboli requiring IVC and pulmonary thrombectomy. This case exposes a potential relationship between mRCC and IVC thrombus with IO agents that creates a critically hypercoagulable state. This issue requires further investigation given the apparent under-reporting of TEs in these patients.