腎細胞癌により2次性膜性腎症を発症したと思われるネフローゼ症候群の1例

Abstract

A 69-year-old man was admitted to our hospital for evaluation of increasing edema. The laboratory findings showed that he had nephrotic syndrome. CT scan and MRI demonstrated a solid mass with a diameter of 4.0cm in the upper pole of the left kidney. Total left nephrectomy was performed on twenty-eighth day after admission. The histopathology of the removed kidney showed membranous nephropathy (MN) accompanied with clear cell renal cell carcinoma (RCC). Nephrectomy did not ameliorate nephrotic syndrome effectively and oral steroid administration was required for the treatment. Although MN is known to be commonly associated with malignancy, there are only 7 case reports describing association of MN with RCC. There is only one case report which showed complete remission of nephrotic syndrome after nephrectomy. We experienced a rare case with MN and RCC. It is essential to investigate the relationship between histological findings and the clinical course for the better understanding of the pathogenesis of tumor-associated MN.