New onset hyperglycemia attributed to renal cell carcinoma

Area of Science:

• Endocrinology
• Oncology
• Nephrology

Background:

• Severe hyperglycemia, indicated by a rise in hemoglobin A1c from 5 to 11.3 mmol/mol, necessitated insulin therapy.
• A 61-year-old male presented with new-onset severe hyperglycemia, unresponsive to initial management.
• Pre-existing chronic kidney disease workup revealed bilateral renal masses on ultrasound.

Observation:

• Magnetic resonance imaging (MRI) confirmed renal masses suspicious for renal cell carcinoma (RCC).
• The patient underwent partial nephrectomy and cryoablation for papillary type RCC.
• Post-surgical pathology confirmed papillary RCC.

Findings:

• Hyperglycemia resolved completely after tumor resection, allowing discontinuation of insulin therapy.
• The patient required only an oral hypoglycemic agent post-operatively.
• This case suggests a rare paraneoplastic syndrome associated with RCC.

Implications:

• Severe hyperglycemia, in the absence of typical causes and concurrent with a renal mass, may indicate an uncommon paraneoplastic syndrome secondary to RCC.
• Understanding the mechanisms, such as ectopic glucagon production or IL-6 pathways, is crucial for managing such rare presentations.
• This case underscores the importance of a multidisciplinary approach in diagnosing and treating complex endocrine-oncologic conditions.