Heterogeneous vascular patterns in renal cell carcinomas

Abstract

The present study proposes a classification of renal cancer tumor blood vessels according to their morphology and maturation grade. We identified four vascular patterns: reticular, diffuse, fasciculated and trabecular. The reticular pattern was present in 63% of cases, being characterized by the predominance of mature CD34+/SMAct+ tumor vessels, highly interconnected. For this pattern, 74% of cases had vascular invasion, and a significant correlation was observed between tumor grade and immature state of tumor vessels (p = 0.022). The diffuse pattern was observed in 23% of cases and was characterized by non-interconnected vessels predominantly of mature CD34+/SMAct+ type and vascular invasion in 64% of cases. Only 8% of cases, had a fasciculate model of vessels distribution, all of them being of mature type, located in the connective axis of papillary renal tumors. For this pattern vascular invasion was found in 50% of cases. In 6% of cases a trabecular pattern was observed and the lowest rate of vascular invasion was registered. We defined here four distinct vascular patterns in renal cell carcinomas showing a strong impact on vascular invasion. A complete morphological and molecular characterization of tumor vessels would be beneficial in elucidating the mechanisms that underlie the ineffectiveness of antiangiogenic/antitumor therapies.

Clinicopathological study of 5 cases of renal cell carcinoma with t(6;11)(p21;q12)

“…Anti-immune check point agents could be hopeful. As downregulation of miR-630 can inhibit the tumor progression in RCC, miR-630 may be a potential therapeutic target also in RCC with t(6;11) (p21;q12) [32,33].…”

Vascular architectural patterns in clear cell renal cell carcinoma and clear cell papillary renal cell carcinoma

“…In contrast to the metastatic potential of CCRCC, ccpRCC shows an indolent behavior; therefore, accurate tumor classification is very important for patients' management and prognosis. Different studies have evaluated the prognostic significance of tumor vascularity in renal cell tumors with two different approaches, either quantification of microvessels by histomorphometry (MVD) [20][21][22][31][32][33][34], or vascular architectural patterns [33,35]. Although Weidner et al [24] have reported that von Willebrand and factor VIII are the most specific vascular markers for measuring intratumoral MVD in solid tumors, they acknowledged that CD31 and CD34 are more sensitive.…”

“…Two recent studies have analyzed vascular architectural patterns in different subtypes of RCC [33,35]. Ferician et al [35] described four patterns using CD34 and SMA.…”

“…Two recent studies have analyzed vascular architectural patterns in different subtypes of RCC [33,35]. Ferician et al [35] described four patterns using CD34 and SMA. Their reticular pattern consisted in vessels with capillary interconnection and reduced intercapillary distance; the diffuse pattern had no interconnected vessels lined by endothelial cells defining a distinct perfused lumen; the fasciculate pattern corresponded to vessels with thin often collapsed lumen restricted to papillary fibrovascular cores; the trabecular pattern consisted of small vessels with a perfused lumen surrounded by prominent perivascular cells.…”

“…MVD in CCRCC has been addressed in previous studies [20][21][22][31][32][33][34]. Vascular architectural patterns have also been previously studied in CCRCC, chromophobe, papillary, and unclassified RCC using CD31, CD34, and SMA [33,35]; however, neither MVD nor vascular architectural patterns have been studied in ccpRCC. ERG, a reliable endothelial cell marker [36], has recently been reported as novel prognostic marker in CCRCC [37], although, at the best of our knowledge, endothelial cell density (ECD) has not been analyzed in renal cell tumors.…”