Frantz-Gruber tumor with atypical presentation as a pancreatic pseudocyst following abdominal trauma: a case report.

Introduction: Solid pseudopapillary neoplasm (SPN) is a rare pancreatic tumor with low malignant potential, mainly affecting young women. Case presentation: A 15-year-old female with prior blunt abdominal trauma presented with epigastric pain and nausea. Laboratory tests showed elevated amylase levels. CT imaging revealed a calcified cystic lesion in the pancreatic head, initially diagnosed as a pancreatic pseudocyst. Due to persistent symptoms and diagnostic uncertainty, surgical exploration was performed. Intraoperatively, a solid-cystic pancreatic head mass adherent to the hepatoduodenal ligament was identified. Frozen-section analysis suggested mucinous neoplasia, leading to pancreatoduodenectomy (Whipple procedure). Final histopathology and immunohistochemistry confirmed SPN with a low proliferative index (Ki-67 < 1%) and no lymph node involvement. Discussion: SPN can mimic pancreatic pseudocysts, particularly following abdominal trauma, leading to diagnostic challenges. Imaging features, such as calcifications and mixed solid-cystic components, may aid in diagnosis. Conclusion: SPN should be considered in the differential diagnosis of pancreatic cystic lesions in young patients, especially when clinical and imaging findings are atypical for pseudocysts.