Application of the indocyanine green fluorescence imaging method in laparoscopic resection of a solitary retroperitoneal metastasis of renal cell carcinoma: A case report.

Fluorescence image-guided surgery has improved intraoperative identification of anatomic structures including visualization of vascular anatomy. Herein, indocyanine green (ICG) fluorescence imaging was applied to identify of a recurrent small tumor of renal cell carcinoma (RCC) during laparoscopic surgery. The patient underwent left laparoscopic radical nephrectomy via the retroperitoneal approach for RCC (clear cell carcinoma, pT1bN0M0) at the age of 39 years. A solitary retroperitoneal mass (14 mm in diameter) was identified in a computed tomography scan 6 years after surgery. We performed laparoscopic resection with the application of the ICG angiography, because RCC is recognized as one of the most hypervascular cancers. The tumor was clearly visualized by fluorescence. Histopathological diagnosis of the resected tumor was recurrent RCC (low grade, G1). The patient remained free of disease at 2 years after surgery. The ICG fluorescence imaging would be a useful method for identification of metastatic small lesions of RCC during laparoscopic surgery.