Solid pseudopapillary tumor of the pancreas in children: 15-year experience at a single institution with assays using an immunohistochemical panel

PURPOSE The aim of this study was to analyze the clinicopathological characteristics of solid pseudopapillary tumor (SPT) of the pancreas and to utilize an immunohistochemical panel to identify specific markers of the disease. METHODS Eleven patients diagnosed with and treated for SPT of the pancreas over the past 15 years were retrospectively analyzed. RESULTS The 11 patients consisted of 8 females and 3 males, of mean age at operation of 13.5 years (range, 10 to 18 years). The most frequent presenting symptom was abdominal pain and/or mass. One patient was referred with hemoperitoneum due to traumatic tumor rupture. The lesions were located in the body, head and tail of the pancreas in four, four, and three patients, respectively. Mean tumor diameter was 7.9 cm (range, 2.5 to 15 cm). Surgical procedures included distal pancreatectomy with splenectomy in four patients, pylorus preserving pancreaticoduodenectomy in four, distal pancreatectomy in two, and subtotal pancreatectomy with splenectomy in one. Mean follow-up was 60.5 months (range, 15 to 126 months). All patients remain alive without tumor recurrence. Immunohistochemical staining showed that all tumors were positive for β-catenin, progesterone receptor (PR), vimentin, and CD99. However, all tumors were negative for E-cadherin and cytokeratin 7 expression. CONCLUSION Patients with SPT of the pancreas have an excellent prognosis after surgical excision. Immunohistochemically, E-cadherin/β-catenin, PR, vimentin, and CD99 would help establish the diagnosis of SPT of the pancreas, although the results of immunohistochemical staining were found to have an indistinct complex immunoprofile.