> [!info] > **Historically termed:** > Solid pseudopapillary epithelial neoplasm (SPEN), Frantz tumor, papillary cystic neoplasm, and Hamoudi tumor. --- ### Key Clinical Features - Rare low-grade malignant pancreatic neoplasm - Strong female predominance (>90%) - Typically presents in adolescents and young women (teens–30s) - Often discovered incidentally or after vague abdominal symptoms > [!tip] > **Classic boards presentation:** > Young woman with a large well-circumscribed mixed solid-cystic pancreatic mass. --- ### Pathogenesis - Characterized by activating **CTNNB1 (β-catenin) mutations** - Associated with abnormal Wnt/β-catenin signaling - Nuclear β-catenin staining is characteristic on immunohistochemistry - The characteristic “pseudopapillary” architecture results from degeneration and discohesion of tumor cells around delicate fibrovascular stalks, creating papillary-like structures rather than true papillae --- ### Clinical Presentation - Frequently asymptomatic - Vague abdominal pain or fullness - Early satiety from mass effect - Occasionally palpable abdominal mass --- ### Imaging Features - Well-circumscribed encapsulated lesion - Mixed solid and cystic appearance - Commonly contains hemorrhagic degeneration - Predilection for pancreatic body and tail - Peripheral or punctate calcifications may be present #### MRI Characteristics - T1 hyperintensity from blood products - Heterogeneous T2 appearance > [!tip] > Hemorrhagic degeneration within a well-encapsulated mixed solid-cystic pancreatic mass in a young woman strongly suggests SPN. --- ### Diagnosis Imaging characteristics combined with patient demographics are frequently diagnostic, and biopsy is not required prior to resection when findings are characteristic. Characteristic pathologic findings include: - Pseudopapillary architecture on cytology/histology - Immunohistochemistry: - Nuclear β-catenin positive - CD10 positive - Vimentin positive --- ### Malignant Potential - Generally indolent despite malignant classification - Approximately 10–15% demonstrate: - Local invasion - Liver metastases - Peritoneal metastases Despite metastatic disease, tumors often remain slow growing and potentially resectable. > [!note] > Unlike pancreatic ductal adenocarcinoma, metastatic SPN may still be approached surgically given the favorable biology. --- ### Treatment - Surgical resection is the primary treatment - Even limited metastatic disease may warrant resection - Minimal established role for chemotherapy or radiation --- ### Prognosis - Excellent long-term outcomes - 5-year survival >95% after resection - Long-term survival remains favorable even in selected patients with metastatic disease