Brain metastasis in a patient with a sarcomatoid variant RCC with well-controlled extracerebral metastases by temsirolimus.

BACKGROUND: The sarcomatoid variant of metastatic renal cell carcinoma (RCC) has often an aggressive course and a poor prognosis, particularly when accompanied with brain metastasis. CASE REPORT: We describe the case of a patient with sarcomatoid variant RCC in whom brain metastasis was observed as a new lesion during treatment with temsirolimus, despite other extracerebral metastatic lesions being well-controlled and progression-free.
RESULTS: This discrepancy between the effectiveness of temsirolimus for extracerebral metastases and the simultaneous progression of brain metastases of RCC raises a concern that while vascular endothelial growth factor (VEGF)-targeted therapy may have clinical efficacy, it may also carry a risk for new brain metastases due to weakening of the structure of the blood brain barrier.
CONCLUSION: This case indicates that computed tomography monitoring of the brain should be regularly performed during VEGF-targeted therapy in patients with sarcomatoid variant RCC, even if brain metastases are absent and extracerebral metastatic lesions are well controlled.