Atypical Presentation of Acute Pancreatitis in an Immunocompetent Patient: A Case Report and Comprehensive Review of the Literature.

Introduction: Acute pancreatitis is a common inflammatory disorder of the pancreas, typically presenting with sudden upper abdominal pain, nausea, and vomiting. Despite its well-documented classic presentation, atypical manifestations can lead to initial misdiagnosis and complicate the clinical course. We present a case of 48-year-old male presented to the Medicine department of DRPGM Case Presentation: C Tanda, H.P, in March 2025, with complaints of left flank pain and fever. He was initially diagnosed as a case of pyelonephritis because there was typical history s/o acute pyelonephritis. Despite treatment with intravenous fluids and antibiotics his symptoms persisted and worsened. Laboratory tests revealed an elevated white blood cell count (23x10³/µL), normal pH and electrolytes, and a CRP of 8 mg/dL. An emergency ultrasound of the abdomen revealed that the pancreas, normal in size and echotexture with mild ascites. The left kidney appeared enlarged with perinephric collection, while the remainder of the abdominal contents was obscured by bowel gas. Ascitic tap was done under aseptic condition for analysis showing significant raised lipase and amylase. Serum lipase sent retrospectively which was significantly elevated (>400 U/L). CECT abdomen performed, revealed acute interstitial pancreatitis with focal changes in the body and tail of the pancreas and minimal pancreatic fluid. The patient was managed conservatively and discharged. While there are cases of atypical presentation of acute pancreatitis in literature, we believe more research is needed to increase awareness in considering the possibility of acute pancreatitis in patients with unresolving and unexplained symptomatology of abdomen. This case illustrates an atypical presentation of acute pancreatitis with flank pain and fev Discussion: er, emphasizing the need for high clinical suspicion and thorough diagnostic evaluation. Acute pancreatitis can present with a wide range of symptoms, complicating timely diagnosis and management. While elevated serum lipase and characteristic imaging findings are diagnostic, atypical presentations may delay appropriate treatment. This case underscores the heterogeneous clinical manifestations of acute panc Conclusion: reatitis and the imperative of contemplating this diagnosis even in the absence of conventional symptoms. Heightened awareness and comprehensive research are essential to elucidate the complete spectrum of atypical presentations, thereby facilitating prompt and accurate diagnosis and management.