Histologic Variants : Clear Cell PanNET
Clear cell variant of PanNET has clear cytoplasm due to large number of lipid vacuoles. It can be seen in von Hippel-Lindau (vHL) disease, multiple endocrine neoplasia (MEN) type 1, and as a sporadic tumor. It may be mistaken for metastatic renal cell carcinoma (RCC) clear cell type, especially in patients with vHL since both clear cell PanNET and RCC can occur in these patients. Immunohistochemistry is helpful in arriving at the correct diagnosis. Metastatic RCC is positive for CD10, vimentin, RCC, and cytokeratin and negative for neuroendocrine markers. Other pancreatic tumors with clear cells that enter into the differential diagnosis include : ductal adenocarcinoma with clear cell features, serous cystadenoma (microcystic adenoma), clear cell variant of solid pseudopapillary tumor, and PEComa. Image courtesy of: Dr. Aatur Singhi (@PancPathologist); used with permission.