Castleman's Disease of the Kidney Mimicking Renal Cell Carcinoma on FDG PET/CT.

Castleman's disease of the kidney is extremely rare. We present a case of Castleman's disease in the left kidney with multiple para-aortic enlarged lymph nodes. Both the renal lesion and para-aortic lymph nodes showed hypervascularity on enhanced CT and minimally increased FDG uptake on FDG PET/CT, mimicking renal cell carcinoma with para-aortic nodal metastases. This case suggests that Castleman's disease should be considered as a rare differential diagnosis in patients with a hypervascular and hypermetabolic renal lesion.