Renal Cell Carcinoma Presenting as Syncope due to Saddle Pulmonary Tumor Embolism.

Pulmonary embolism (PE) is defined as the obstruction of the pulmonary artery or one of its branches by a blood clot, tumor, air, or fat emboli originating elsewhere in the body. A saddle PE occurs when the obstruction affects the bifurcation of the main pulmonary artery trunk. We present a case of a 46-year-old man who presented to our hospital due to an episode of syncope. Computed tomography angiography (CTA) of the chest showed extensive PE and abdominal CT scan showed a large 8 cm left renal mass with inferior vena cava (IVC) thrombus. Emergent embolectomy, left total nephrectomy, and IVC tumor removal were performed yielding the diagnosis of clear cell renal cell carcinoma (RCC). Interestingly, our patient did not experience any symptoms related to his RCC until the diagnosis of PE due to syncope, and the asymptomatic tumor was found out to be the possible cause of this PE due to the presence of tumor cells constituting the tumor embolus. It is thus recommended to improve the early screening process for RCC. Besides, clinicians should pay attention to patients presenting with uncharacteristic symptoms of RCC who might present with symptoms of saddle PE.