OBJECTIVETo compare the clinicopathological characteristics and prognosis of patients with small (≤5 cm) solid pseudopapillary neoplasm of the pancreas (SPN) and those with large (>5 cm) SPNs.

METHODSWe retrospectively analyzed the clinical characteristics, laboratory findings, radiological features, treatment and prognosis of 148 patients with histologically confirmed SPN between August, 2006 and December, 2014 and compared the data between patients with small SPNs (≤5 cm) and those with large SPNs (>5 cm).

RESULTSIn the large SPN group, the female-to-male ratio was significantly higher than that in small SPN group (61/8 vs 56/23, P=0.009) and the patients were significantly younger in large SPN group (28.3±12.3 vs 33.0±11.4 years, P=0.016). Small SPNs (≤5 cm) typically presented as inhomogeneous solid or cystic tumors, while large SPNs (>5 cm) often appeared as homogeneous solid and cystic tumors, but they did not show any significant difference in aggressive behaviors (P=0.288). The 5-year disease-free survival of patients with small SPNs was 100%, and the 1-, 3-, and 5-year disease-free survival of patients with large SPNs was 98.6%, 94.9%, and 89.3%, respectively (P=0.030), showing no significant differences in the overall survival between the two groups.

CONCLUSIONSmall SPNs and large SPNs have different clinical characteristics. Even with complete resection, tumors larger than 5 cm are more likely to have tumor recurrence and metastasis, and close follow-up is recommended for these patients.