Oncologic Safety and Lymphadenectomy in Parenchyma-Sparing Resection for SPN (PSR for SPN)

Solid pseudopapillary neoplasm (SPN) is a rare pancreatic tumor, accounting for approximately 1-3% of all pancreatic neoplasms, and predominantly affects young women . Although historically classified as a borderline lesion, SPN is currently regarded as a low-grade malignant neoplasm with an excellent long-term prognosis, with complete surgical resection achieving cure in 85-95% of patients. Even in the presence of recurrence or limited distant metastasis, aggressive surgical management can still result in prolonged survival. Given this indolent biological behavior and long life expectancy, the primary surgical challenge in SPN has gradually shifted from achieving oncologic radicality alone to balancing oncologic safety with long-term functional preservation.

Parenchyma-sparing resection (PSR) has therefore gained increasing attention in the management of SPN. By preserving pancreatic parenchyma and avoiding complex gastrointestinal reconstruction, PSR has the potential to reduce surgical trauma and preserve long-term endocrine and exocrine function. However, concerns persist regarding its oncologic adequacy, particularly the risk of positive resection margins, limited lymph node assessment, and postoperative morbidity. Current evidence supporting PSR in SPN remains largely derived from small retrospective series, and robust data addressing long-term oncologic outcomes and functional consequences are lacking.

Owing to the rarity and low malignant potential of SPN, prospective randomized trials comparing PSR with conventional oncologic resection (OR) are unlikely to be feasible. Consequently, optimal surgical strategy for SPN remains controversial. Using a large, prospectively maintained database, this study aimed to compare PSR and OR with respect to long-term oncologic outcomes, perioperative safety, and postoperative functional preservation. In addition, given the extremely low incidence of lymph node metastasis in SPN, we sought to further evaluate the necessity of routine lymph node dissection from a long-term outcome perspective.