The International Society of Urological Pathology (ISUP) Vancouver Classification of Renal Neoplasia

Abstract

The classification working group of the International Society of Urological Pathology consensus conference on renal neoplasia was in charge of making recommendations regarding additions and changes to the current World Health Organization Classification of Renal Tumors (2004). Members of the group performed an exhaustive literature review, assessed the results of the preconference survey and participated in the consensus conference discussion and polling activities. On the basis of the above inputs, there was consensus that 5 entities should be recognized as new distinct epithelial tumors within the classification system: tubulocystic renal cell carcinoma (RCC), acquired cystic disease-associated RCC, clear cell (tubulo) papillary RCC, the MiT family translocation RCCs (in particular t(6;11) RCC), and hereditary leiomyomatosis RCC syndrome-associated RCC. In addition, there are 3 rare carcinomas that were considered as emerging or provisional new entities: thyroid-like follicular RCC; succinate dehydrogenase B deficiency-associated RCC; and ALK translocation RCC. Further reports of these entities are required to better understand the nature and behavior of these highly unusual tumors. There were a number of new concepts and suggested modifications to the existing World Health Organization 2004 categories. Within the clear cell RCC group, it was agreed upon that multicystic clear cell RCC is best considered as a neoplasm of low malignant potential. There was agreement that subtyping of papillary RCC is of value and that the oncocytic variant of papillary RCC should not be considered as a distinct entity. The hybrid oncocytic chromophobe tumor, which is an indolent tumor that occurs in 3 settings, namely Birt-Hogg-Dubé Syndrome, renal oncocytosis, and as a sporadic neoplasm, was placed, for the time being, within the chromophobe RCC category. Recent advances related to collecting duct carcinoma, renal medullary carcinoma, and mucinous spindle cell and tubular RCC were elucidated. Outside of the epithelial category, advances in our understanding of angiomyolipoma, including the epithelioid and epithelial cystic variants, were considered. In addition, the apparent relationship between cystic nephroma and mixed epithelial and stromal tumor was discussed, with the consensus that these tumors form a spectrum of neoplasia. Finally, it was thought that the synovial sarcoma should be removed from the mixed epithelial and mesenchymal category and placed within the sarcoma group. The new classification is to be referred to as the International Society of Urological Pathology Vancouver Classification of Renal Neoplasia.

Early-stage clear cell tubulopapillary renal cell carcinoma: imaging features and distinction from clear cell and papillary subtypes

“…The finding that CCTPRCC cannot be differentiated from ccRCC is supported by several pathology studies that have described CCTPRCC as a mimicker of ccRCC [1][2][3]11]. For example, pathologists may have difficulty distinguishing CCTPRCC from ccRCC with a low Fuhrman grade [1,2,4], and rely on immunohistochemistry to render the correct diagnosis [1-4, 7-9, 11, 24].This study had several limitations. The study was retrospective; however, the readers were blinded to each patient's pathologic diagnosis in order to minimize bias.…”

Toward an improved definition of the genetic and tumor spectrum associated with SDH germ-line mutations

“…SDH-deficient RCC is a unique subtype of RCC that has been recently accepted as a provisional entity in the 2013 International Society of Urological Pathology Vancouver Classification. 43 SDH-deficient RCCs display a slight male predisposition, present as bilateral tumors in 25% of cases, and have stereotypical morphologic features, that is, solid or focally cystic growth, uniform cytology with eosinophilic flocculent cytoplasm, intracytoplasmic vacuolations and inclusions, round to oval low-grade nuclei, and SDHB immunonegativity. 44,45 SDHA-negative IHC was reported once, but no mutational screening of SDHA was performed.…”

Renal cell carcinoma with angioleiomyoma-like stroma: clinicopathological, immunohistochemical, and molecular features supporting classification as a distinct entity

“…It has been suggested that previously reported examples of CK7-positive clear cell renal cell carcinomas 38 are in fact clear cell papillary renal cell carcinomas. 12 However, as clear cell papillary renal cell carcinomas lack chromosome 3p deletion and these tumors did not exhibit such morphology, the possibility that another subtype of CK7-positive 'clear cell' renal neoplasm exists remains open to further study.…”

“…4 As only a small number of tumors with these features have been reported and their clinicopathological, immunohistochemical, and molecular features are incompletely understood, it is unclear whether these lesions comprise a single distinct type of renal neoplasm or whether these reports encompass multiple entities. The relationships of these tumors to clear cell renal cell carcinoma 4 and clear cell papillary renal cell carcinoma [5][6][7][8][9][10][11] (also known as clear cell tubulopapillary renal cell carcinoma) 6,12 are also poorly understood. 13 To elucidate the characteristics of these tumors and assess whether they represent a distinct subcategory of renal neoplasia, we studied the clinicopathological, immunohistochemical, and molecular features of renal epithelial neoplasms noted to have a smooth muscle stromal component from our pathology archives.…”