Solid pseudopapillary neoplasms: A case series and review of literature

Abstract

Solid pseudopapillary neoplasm (SPPN) of the pancreas is a rare tumor entity that arises from different pancreatic parts constitutes up to 2.5% of all pancreatic neoplasms. We addressed special focus on the general descriptive features of SPPNs regarding age, gender, symptoms, diagnostic tools, pathological features, surgery, and outcome. SPPN has low malignant potential. It usually discovered incidentally with great predilection to occur in young women in about 90% of reported cases. SPPNs exhibit benign characteristics in most of cases reported with low tendency toward malignant behavior. Tumor size may reach up to 10 cm and the prevalent sites of tumor occurrence are the head and tail of the pancreas comprising 40% and 30%, respectively. SPPNs tend to arise as single pancreatic mass, but some reported cases of multicentric SPPN. Endoscopic ultrasound (EUS)-guided fine needle aspiration (EUS-FNA) is used as a preoperative diagnostic tool with sensitivity and specificity of 90% and 94%, respectively. Surgical resection is the standard of care for treatment of such neoplasms as it achieves cure and prolongs patient survival. Long-term prognosis is evidently excellent with 5-year survival rates ranging 95%–97%. In addition, 10-year survival may be as high as 90%, but these data are limited. Nonresectable tumors are treated by surgical debulking. In our series, we identified 18 cases of SPPN confirmed by histopathological examination. Female to male ratio is 9:1, and mean age was 29 with an average of 5.5 years. The oldest of our patients was a 70-year-old male. All patients presented with abdominal pains; some presented with anorexia and weight loss. EUS showed a soft tissue mass with multiple cystic areas that represented areas of internal hemorrhage. The size ranged from 2 cm up to 10 cm. Eight masses were located in the body, 7 in the head, 2 in the tail, and only one case in the uncinate process. The cytopathological study demonstrated single cells, small loose clusters, and scattered intact papillary structures with delicate fibrovascular cores, finely granular cytoplasm, and nuclei with fine chromatin. No distant metastasis was observed. EUS-FNA was done in all cases using a 22G needle and revealed SPPN in all cases. Distal pancreatectomy or modified Whipple operation was done and final histopathology confirmed the diagnosis. Only one patient operated by Whipple resection complicated by postoperative abdominal sepsis and died 2 weeks later. Follow-up for at least 2 years for the rest of the patients revealed no recurrence.