Solid-pseudopapillary tumor of the pancreas: A typically cystic carcinoma of low malignant potential

Solid-pseudopapillary tumors are uncommon neoplasms of low malignant potent ial generally occurring in young women. They often cause few symptoms and m ay reach a large size by the time they are detected, Degenerative cystic ch anges are common, and the clinical presentation is often that of a cystic p ancreatic tumor. Pathological features include solid, cellular, hypervascul ar regions without gland formation, and degenerative pseudopapillae. The ce lls contain eosinophilic granules rich in alpha-1-antitrypsin and the nucle i are typically grooved. Despite its characteristic microscopic appearance, the immunophenotype (positive for vimentin, alpha-1-antitrypsin, and neuro n specific enolase) Is nor specific and does not define a line of different iation corresponding to any normal pancreatic cell type. Ultrastructural st udies have also failed to identify specific differentiated features. Noneth eless, the biological behavior of solid-pseudopapillary tumor is well estab lished. The tumor is indolent, with infrequent metastases to liver or perit oneum and usually long survival, even in the presence of disseminated disea se. Copyright (C) 2000 by W.B. Saunders Company.