Rare Case of Acute Pancreatitis With Normal Lipase Level

Abstract

Introduction: Acute pancreatitis can be diagnosed with one of the following criteria: clinical symptoms of pancreatitis, radiological findings and/or elevated serological markers for pancreatitis. However, there is very limited literature on acute pancreatitis with normal lipase level. Case description: 64 yo female with h/o hypertension and chronic back pain, presented with acute onset severe non-radiating epigastric pain, nausea and vomiting. She was not a smoker but drinks 4-5 glasses of hard liquor once every week. Significant examination findings: BP 153/100 mmHg, HR irregularly irregular, severe epigastric tenderness with no guarding or rigidity. Significant lab results included: lipase 30 U/L, calcium level 9.9 mg/dl, WBC count 17500 thou/uL, glucose 132 mg/dl, total bilirubin 1.7 mg/dl, direct bilirubin 0.5 mg/dl, normal transaminases. The liver function test normalized on day 2. CT abdomen and pelvis with IV contrast: acute edematous pancreatitis with extensive atherosclerotic plaques with 30% narrowing in the proximal SMA and no gall stones. IgG-713 mg/dl, IgG4- 45.9 mg/dl (normal). On admission in the ED, she was also found to be in atrial fibrillation with RVR (175/min) and further tests for causes of atrial fibrillation revealed elevated free T4 level- 3.44 and suppressed TSH- 0.01- primary hyperthyroidism. She had no symptoms of hyperthyroidism except for minimal weight loss. She was improved with conservative management and was discharged. Discussion: There are very few cases of acute pancreatitis with normal lipase level in literature. Lipase level has 55-100% sensitivity and 94-100% negative predictive value in the diagnosis of acute pancreatitis. Whereas contrast enhanced CT scan has 92% sensitivity and 100% specificity in diagnosing pancreatitis. Autoimmune pancreatitis should be a consideration in patients with normal lipase level and checking IgG4 level can be of value. When negative in such patients like our patient, clinical and imaging findings can suffice the diagnosis of acute pancreatitis.Figure 1