Abstract
Histopathological Classification of renal tumors is more complicated every year. New emerging entities are defined not only by morphology and immunohistochemical profile, but also more frequently using molecular genetic techniques.
In this review, new perspective entities with clearly defined molecular-genetic background are introduced. Groups of renal tumors sharing abnormalities in the mTOR pathway were recognized recently.
It is eosinophilic solid and cystic renal cell carcinoma, high grade oncocytic tumor, and low grade oncocytic tumor. All subtypes follow an indolent non aggressive course despite presence of high-grade nuclei.
MitF related renal cell carcinomas (translocation) renal cell carcinomas were listed in WHO classification since 2004. New member of RCC with impaired TFEB gene is renal cell carcinoma with TFEB amplification.
This subtype is aggressive (contrary to TFEB translocated RCC) and very difficult to diagnose. Several other entities are intensively studied and examined.
Their current status is questionable and more likely they will not be listed in upcoming WHO classification. Despite the rapid progression in diagnostic abilities, practical impact for routine clinical practice is (in 2020) limited.
Conclusions: Urologists and oncologists should expect new, relatively complicated classification of renal tumors, partly based on molecular genetic features. However, a more personalized approach to individual patients is desirable, clinical specialists do not dispose appropriate spectrum of systemic treatment modalities.