Characteristics and Outcomes of Solid Pseudopapillary Tumors of Pancreas: A US Multicenter Retrospective Study

Introduction: A solid-pseudopapillary tumor (SPT) of the pancreas is a rare neoplasm accounting for 0.2-2.7% of pancreatic neoplasms. It has a low malignant potential and arises mainly in young females. Data regarding the characteristics and outcomes of SPTs in the US is limited. We describe the characteristics and outcomes of 11 cases of SPTs. Methods: A multicenter retrospective observational study was conducted and electronic medical records of patients diagnosed with SPT were reviewed between 2017 to 2023. Demographics, and lesion characteristics including size, location, imaging, pathological characteristics, and outcomes were obtained. Data were analyzed using descriptive statistics. Results: SPT of the pancreas was found in 11 patients, including 9 females (81%) and 2 males (19%), with a median age of 24.5 years (range, 22-71). The median size of the lesion was 2.1 cm (range, 6.2-2 cm). 63% of tumors were located in the head of the pancreas, 27% in the tail of the pancreas, and 9% in the neck of the pancreas. Imaging studies including Computed tomography and Magnetic Resonance imaging showed lesions to appear complex, solid, and cystic lesions. Endoscopic ultrasound (EUS) showed 63% of lesions were hypoechoic, 9% isoechoic, 9% hyperechoic, and 9% cystic. Fine needle aspiration biopsy showed the solid pseudopapillary tumor. Complete Surgical resection was performed in all cases without complications. Follow-up did not show any recurrence (Figure 1, Table 1). Conclusion: Based on our study SPTs of the pancreas were more commonly seen in young females. Most lesions were located in the head of the pancreas and were well-circumscribed and hypoechoic rather than cystic on EUS. Curative surgical resection was achieved in all cases. The long-term prognosis of patients is very good, although tumors can recur. Further studies are needed to validate our findings.Figure 1.: A) CT image showing a mass in the head of the pancreas. B & C) EUS D: Histology showing SPT. Table 1. - Characteristics of Patients With Solid Pseudopapillary Tumor of the Pancreas Age Sex Race Family History Location of Tumor Size in cm EUS Characteristics FNA Pathology Surgery 28 F White No NOP 2 X 1.8 Hypoechoic SPT SPT yes 71 F White No TOP 2.1 X 1 Hypoechoic SPT SPT yes 31 F African American No HOP 5 X 4.6 Isoechoic SPT SPT yes 22 F Hispanic No HOP 6.2 X 4.8 Hyperechoic SPT SPT yes 28 F Hispanic No TOP 6 X 5.2 Mixed SPT SPT yes 20 M African American No HOP 6 X 5.5 Hypoechoic low-grade tumor favors SPT SPT yes 30 F Hispanic No HOP 5 X 5.5 Cystic SPT SPT yes 23 F Hispanic No TOP 6.1 X 4 Hypoechoic SPT SPT yes 32 F Hispanic No HOP 3.5 Hypoechoic SPT SPT yes 48 M White No HOP 4.5 Hypoechoic uniform round cells SPT yes 42 F White No HOP 2.9 Hypoechoic SPT SPT yes HOP: Head of the Pancreas, TOP: Tail of the Pancreas, NOP: Neck of the Pancreas.