Extreme Hyperlipasemia in End-Stage Renal Disease Mimicking Acute Pancreatitis: A Diagnostic Pitfall.

Marked elevations of pancreatic enzymes are commonly interpreted as evidence of acute pancreatitis. However, in patients with end-stage renal disease (ESRD), serum amylase and lipase may be elevated without pancreatic inflammation, posing a significant diagnostic challenge. We present a case illustrating the diagnostic dilemma of extreme pancreatic enzyme elevation in an ESRD patient undergoing peritoneal dialysis without clinical or radiologic evidence of pancreatitis. A 50-year-old man with ESRD on peritoneal dialysis and known gastroparesis presented with intractable nausea and vomiting. Initial laboratory testing revealed markedly elevated pancreatic enzymes, with lipase levels peaking above 4,000 U/L and serum amylase at 545 U/L, raising concern for acute pancreatitis. However, the patient lacked characteristic epigastric pain, and contrast-enhanced abdominal CT demonstrated a normal pancreas without inflammatory changes or peripancreatic fluid collections. Autoimmune pancreatitis was excluded with negative IgG4 levels. Analysis of peritoneal dialysis fluid revealed very low amylase levels (less than 30 U/L), arguing against pancreatic enzyme leakage into the peritoneal cavity. Enzyme levels gradually declined over the course of hospitalization, and polyethylene glycol precipitation testing was pursued to evaluate for macroenzyme formation. The marked discordance between extremely elevated serum pancreatic enzymes and the absence of clinical symptoms, radiologic abnormalities, or dialysate enzyme elevation strongly suggested macrolipasemia and macroamylasemia in the context of ESRD. These findings likely reflect reduced renal clearance and macroenzyme complex formation rather than true pancreatic inflammation. This case highlights that extreme elevations of pancreatic enzymes may mimic acute pancreatitis in ESRD patients despite the absence of pancreatic disease. Careful correlation of symptoms, imaging findings, dialysis fluid analysis, and targeted laboratory testing is essential to avoid misdiagnosis and unnecessary interventions. Recognition of macroenzyme-associated hyperlipasemia should be considered when evaluating dialysis patients with markedly elevated pancreatic enzymes.