Multi-centric solid-pseudopapillary neoplasm of the pancreas.

Multi-centric solid-pseudopapillary neoplasm (SPN) of the pancreas is a rare tumor: only 4 cases are reported in the literature. The clinical and pathological features have not yet been fully clarified. We report 3 cases of multi-centric SPN and discuss their clinical presentations and histological and immunohistochemical features, comparing with solitary SPN. Among the total of 7 cases, 6 were female and 1 was male. Patients had nonspecific symptoms at presentation. Tumors were often large and well demarcated with cystic degeneration and clear margin between lumps. Histologically, characteristic pseudopapilla was formed with uniform cells surrounding the delicate blood vessels. Tumor cells were positive for vimentin, synaptophysin, progesterone receptor, and CD10 and demonstrated nuclear localization of β-catenin. The prognosis of patients was excellent after complete surgical resections. Multi-centric SPN shares similar clinical and pathological features to solitary SPN.