Massive calcified solid pseudopapillary neoplasm of the pancreatic head.

Solid pseudopapillary neoplasm (SPN) of the pancreas is an uncommon, low-grade malignant tumor, accounting for less than 3% of all exocrine pancreatic neoplasms. Although typically indolent, SPN poses significant diagnostic challenges and must be distinguished from other pancreatic tumors to guide appropriate management. We present the case of a 31-year-old woman with a two-year history of right upper abdominal pain which had recently worsened. Laboratory investigations, including tumor markers, were within normal limits. Imaging revealed a massive, lobulated pancreatic head tumor with solid, cystic, and calcified components. The mass was in close contact with the duodenum, the splenomesenteric confluence, and the right colic flexure, without evidence of invasion. The patient underwent a cephalic pancreaticoduodenectomy (Whipple procedure). Gross examination showed a well-encapsulated 12.5 × 9 × 8 cm mass with cystic degeneration, hemorrhage, and coarse calcifications. Histological examination revealed solid and pseudopapillary architecture with low mitotic activity and degenerative changes. Immunohistochemistry demonstrated positivity for β-catenin and CD10, confirming the diagnosis of SPN. Complete surgical resection is associated with an excellent prognosis, although rare aggressive behavior has been reported. This case underscores the diagnostic value of integrating imaging, histopathology, and immunohistochemistry. It also highlights the importance of considering SPN in the differential diagnosis of large, calcified pancreatic masses in young women.