Current Knowledge and Prospects for Renal Hemangioblastoma and Renal Cell Carcinoma with Hemangioblastoma-like Features

Abstract

Tumors exhibiting histopathological findings similar to those of hemangioblastoma of the central nervous system (CNS-HB) rarely develop in the kidneys. Currently, renal hemangioblastoma (RHB) is considered analogous to CNS-HB; however, they differ in gross appearance, as well as immunohistochemical and molecular findings. In contrast, some renal cell carcinomas reportedly comprise distinct, clear cell renal cell carcinoma (CCRCC)- and hemangioblastoma (HB)-like areas. Initially, renal cell carcinomas with HB-like features (RCC-HBs) were considered a morphological variant of CCRCC owing to their diverse histological findings. However, the immunohistochemical and molecular findings of RCC-HBs suggest that RCC-HB is distinct from CCRCC. Additionally, one of the RCC-HBs had a focal leiomyomatous stroma and TSC2 variant, suggesting that RCC-HB and RCC with fibromyomatous stroma (RCC-FMS) might belong to the same disease entity. Therefore, we comprehensively reviewed the clinical, pathological, and molecular features of RHB, RCC-HB, and the related tumors and discussed the similarities, differences, and relationships between them. We believe that our review would serve as a foundation for further investigation on elucidating the relationship between CNS-HB, RHB, RCC-HB, and RCC-FMS.

Recurrent Tuberous Sclerosis Complex/Mammalian Target of Rapamycin Mutations Define Primary Renal Hemangioblastoma as a Unique Entity Distinct From Its Central Nervous System Counterpart

“…Upon molecular examination, 2 of these RCCs were found to harbor a recurrent mutation in mTOR , 34 and another harbored a mutation in TSC2. 35 As proposed by Kojima et al, 34,36 the histologic, IHC, and molecular profiles of RCC with HB-like features shared similarities with RCC with fibromyomatous stroma (RCC FMS), 16 suggesting that RCC with HB-like features may be on the same spectrum as RCC FMS with TSC/mTOR mutations. In our study, renal HBs also exhibited a thick encapsulation that extended into the tumor periphery and occasionally penetrated inside the tumor, and were characterized by recurrent mutations in the TSC/mTOR genes.…”