Pancreatic intraductal papillary mucinous neoplasm with sarcomatous transformation. A case report / Transformación sarcomatosa de neoplasia papilar mucinosa intraductal pancreática. Reporte de un caso

Mixed pancreatic epithelial and mesenchymal tumors are rare, usually invasive, entities. Intraductal papillary mucinous neoplasm (IPMN) is a precursor of invasive ductal carcinoma and shares mutations with its invasive counterparts. We report the case of a 72-year-old female with a previously undescribed sarcomatous transformation of a residual IPMN with no evidence of an invasive component. The mesenchymal component showed no heterologous differentiation. Both the epithelial and the mesenchymal populations showed aberrant expression of p53 protein and the same point mutation in KRAS gene. After a 6 month follow up, there were no signs of local or distant relapse. The present case suggests that sarcomatous transformation is possible in non-invasive, intraductal pancreatic lesions.(AU)

Las neoplasias pancreáticas mixtas son entidades raras que usualmente asocian comportamientos invasivos. La neoplasia papilar mucinosa intraductal (NPMI) es una lesión precursora del carcinoma invasivo que comparte con este último mutaciones clave. En el presente estudio se reporta por primera vez una transformación sarcomatosa sobre NPMI residual sin evidencia de componente infiltrante en una paciente de 72años. El componente mesenquimal no mostró diferenciación heteróloga. Tanto la población mesenquimal como la epitelial mostraron tinción aberrante para p53 y albergaban la misma mutación en el gen KRAS. Tras 6meses de seguimiento, la paciente no mostró signos de recaída local ni a distancia. El presente estudio demuestra que es posible una transformación sarcomatosa sobre NPMI.(AU)

Pancreatic intraductal papillary mucinous neoplasm with sarcomatous transformation. A case report.

Mixed pancreatic epithelial and mesenchymal tumors are rare, usually invasive, entities. Intraductal papillary mucinous neoplasm (IPMN) is a precursor of invasive ductal carcinoma and shares mutations with its invasive counterparts. We report the case of a 72-year-old female with a previously undescribed sarcomatous transformation of a residual IPMN with no evidence of an invasive component. The mesenchymal component showed no heterologous differentiation. Both the epithelial and the mesenchymal populations showed aberrant expression of p53 protein and the same point mutation in KRAS gene. After a 6 month follow up, there were no signs of local or distant relapse. The present case suggests that sarcomatous transformation is possible in non-invasive, intraductal pancreatic lesions.