Incidentally diagnosed renal cancer following investigation for new-onset hyperglycemia

Detecting paraneoplastic syndrome is important for the diagnosis of renal cancer. We present an incidentally detected case of renal cancer during the investigation of new-onset hyperglycemia in a 68-year-old woman. The patient presented with palpitations and weight loss; her laboratory findings showed hyperglycemia, anemia, and elevated C-reactive protein and alkaline phosphatase levels. Computed tomography revealed a right renal cancer. Following tumor removal, her glycemic control improved, and insulin therapy, which was needed preoperatively, was not needed anymore. Clinicians should suspect renal cancer in patients with new-onset hyperglycemia occurring simultaneously with interleukin-6-associated paraneoplastic syndrome.