Philippine Journal of Surgical Specialties Vol. 78, No. 2, July-December 2023, pp 53-60

Extra pancreatic Primary Retroperitoneal Solid Pseudopapillary Neoplasm: A Case Report

Author(s): Ashley T. Dionisio, MD and Bayani B. Tecson, MD, FPCS, FPALES, FPSPSManlubatan, MD

Solid pseudopapillary neoplasm (SPN) is a rare pancreatic neoplasm. This case reports a 63-year-old female previously diagnosed with bilateral adrenocortical carcinoma post resection who presents with persistent epigastric pain. Suspicions for recurrence prompted diagnostics revealing retro pancreatic and left suprarenal foci, both suspicious for malignancy. Resection of both tumors yielded a moderately to poorly differentiated retro pancreatic carcinoma with differentials not limited to recurrence and pancreatic neuroendocrine tumor with a left suprarenal lymph node. Immunohistochemistry was then done and was consistent with SPN having a strong expression for b-catenin, vimentin, pan cytokeratin. It was non-specific to melan-A and negative for chromogranin A, synaptophysin, inhibin-a and CD10. At 6 months’ follow up, patient is clinically well and abdominal CT scan showed no recurrence. SPNs can masquerade as other neoplasms having similar clinical, radiologic and histopathologic features. Immunohistochemistry thus plays a crucial role for accurate diagnosis and management. Surgical resection still remains the treatment of choice and can provide a 95% overall survival rate, while limited evidence supports the use of adjuvant chemotherapy or radiation.

Key words: Solid pseudopapillary neoplasm, extra pancreatic, immunohistochemistry