Serous neoplasms of the pancreas share many, but not all aspects of their microvascular and angiogenic profile with low-grade clear cell renal cell carcinomas

Abstract

Similarly to clear cell renal cell carcinomas (CCRCC), serous neoplasms (SN) of the pancreas frequently show inactivation of VHL gene, clear cell histology and abundant microvasculature. Data on the microvascular and angiogenic profile of SN are scarce. Aiming to examine further the striking resemblance of clear cell epithelial neoplasia in pancreas and kidney, we compared the microvascular profile and expression of pro-angiogenic factors in SN and in CCRCC using immunohistochemical stains. SN and CCRCC shared a predominance of differentiated blood vessels, scarcity of lymphatic vessels, presence of CD105 and claudin-5 in tumoral vessels, expression of vascular endothelial growth factor (VEGF)-A, cyclooxygenase-2 (COX-2), carbonic anhydrase IX in tumoral cells, and lack of VEGF-C in tumoral cells. In contrast to CCRCC, SN showed lower pericyte coverage of vessels, lower blood vessel endothelial cell proliferaction fraction, more pronounced VEGF receptor (VEGFR)-2 and glucose transporter-1 expression, higher inducible (iNOS) but lower endothelial nitric oxide synthase (eNOS) expression, as well as presence of VEGFR-3 and D2-40 expression in epithelial cells. In conclusion, we found a significant similarity but not equality of microvascular biology of SN and CCRCC. We recognized VEGFR-2, VEGFR-3, COX-2, iNOS, eNOS and D2-40 as new markers of epithelial cells of SN of the pancreas.