Tumeur des cellules épithélioïdes périvasculaires (PECome) du pancréas

Neoplasms with perivascular épithelioid-cell differentiation (PEComas) are rare tumors with a distinctive immunoreactivity for melanocytic markers. They have been described in various organs. We report an intrapancreatic PEComa discovered in a 46-year-old woman during a workup for diarrhea. CT scan showed a 1.7 cm nodule in the body of the pancreas with slight-contrast enhancement at arterial time and isodense at portal time. The aspect was suggestive of an endocrine tumor despite negative somatostatin-receptor scintigraphy. Enucleation was performed. Pathologic evaluation showed a well-circumscribed intrapancreatic tumor consisting of a population of clear to eosinophilic spindle cells and a less abundant population of epithelioid cells arranged around blood vessels. Tumor cells expressed vimentin, HMB45 and actin and only focally S-100 protein, KL1, CD117 and CD34. These features were consistent with a PEComa. Pancreatic PEComas are rare, but should be included in the differential diagnostic of pancreatic clear cells tumors or pancreatic spindle- and epithelioid-cells tumors.