Renal Cell Carcinoma–Associated Diabetes Mellitus Due to Paraneoplastic Syndrome in Maintenance Hemodialysis: A Case Report

A 59-year-old Japanese woman with a 22-year history of long-term hemodialysis was admitted to our hospital for further examination of hyperglycemia and anemia. Five months before hospitalization, her fasting plasma glucose value was 99 mg/dL and her glycated hemoglobin was 5.7%. On admission, her fasting plasma glucose value was 873 mg/dL, glycated hemoglobin was 16.2%, C-peptide reactivity was 22.3 ng/mL (reference range, 0.5-3.0), and homeostasis model assessment of insulin resistance (HOMA-IR) was 10.6 (reference range, <2.0); the high HOMA-IR indicated high insulin resistance. Intensive insulin therapy was started for hyperglycemia, which required more than 40 units/day. Computed tomography showed a hypervascular lesion 2.2 cm in diameter on the right kidney; therefore, right nephrectomy was performed. Complete resection was confirmed, and the lesion was diagnosed as a clear cell type of renal cell carcinoma (RCC). Immediately after nephrectomy, glycemic control normalized and administration of insulin was discontinued. Fourteen days after nephrectomy, the HOMA-IR decreased to 2.96. RCC that develops in patients receiving long-term hemodialysis has been reported to be dialysis-related RCC, but there have been no reports suggesting a relationship between dialysis-related RCC and diabetes. To our knowledge, this is the first report of RCC presenting with the paraneoplastic syndrome of acute-onset diabetes because of insulin resistance.