Papillary cystic and solid tumors of the pancreas: A pancreatic embryonic tumor? Studies of three cases and cumulative review of the world's literature

Background. The papillary cystic and solid tumor of the pancreas is rare. It occurs predominantly in young women, and most present a benign behavior. The pathogenesis of this tumor has attracted a number of investigations but remains unclear. Methods. We present three patients with this tumor and a review of 289 others from the world's literature, a total of 292 cases. On the basis of the analyses of the clinical and pathologic features from the reported cases, the pathogenesis of this unusual tumor has been further explored. Results. Ninety percent of the patients were female, with a mean age of 23.9 years. The tumors were usually quite large with a mean diameter of 10.3 cm. Ninety-two percent of these tumors were totally or partially cystic. Rupture of the capsule resulted in hemoperitoneum in eight cases, five of which were without any identifiable cause. Forty-three tumors (14.7%) have been recognized as malignant. The overall prognosis has been excellent and an aggressive approach to resection is indicated. Conclusions. The results of immunohistochemical staining and electromicroscopy were rather diverse, but most, including the current cases, support the hypothesis that the tumor originates from pleuripotential embryonic stem cells. Thus the term pancreatic embryonic tumors seems preferable to papillary cystic and solid tumor of the pancreas to delineate the origin of the tumor and to reflect some of its biologic characteristics.