Figure 1

Expression of pancreatic duct adenocarcinoma-associated markers Dpc4, 14-3-3 sigma, beta-catenin, topoisomerase II alpha in solid pseudopapillary tumors, pancreatoblastomas, undifferentiated carcinomas with osteoclastic-like giant cells, and acinar cell carcinomas. Dpc4 expression was seen in all solid pseudopapillary tumors (a1), pancreatoblastomas (a2), undifferentiated carcinomas with osteoclastic-like giant cells (a3), and acinar cell carcinomas (a4). All but one solid pseudopapillary tumors (b1), pancreatoblastomas (b2), and acinar cell carcinomas (b4) expressed 14-3-3 sigma but only one of four undifferentiated carcinomas with osteoclastic-like giant cells (b3) did. Nuclear beta-catenin staining was seen in seven of eight solid pseudopapillary tumors (c1), all four pancreatoblastomas (c2) but only focally in one of 13 acinar cell carcinomas (c4). No undifferentiated carcinoma with osteoclastic-like giant cells showed nuclear staining of beta-catenin (c3). None of the solid pseudopapillary tumors (d1) and undifferentiated carcinomas with osteoclastic-like giant cells (d3) expressed topoisomerase II alpha (nuclear staining), whereas half of the pancreatoblastomas (d2) and most of the acinar cell carcinomas (d4) showed focal staining.