Mutated ASXL1 upregulates mTOR expression in renal cell carcinoma with fibromyomatous stroma

AbstractRenal cell carcinoma with fibromyomatous stroma (RCC FMS), defined as an “emerging entity” in the 2016 WHO classification and recommended to be a novel entity by GUPS, is represented by tumor cells with clear to mildly eosinophilic cytoplasm displaying elongated and branching tubules and papillae. A fibromyomatous stroma could be observed in these tumors. These tumor s are immunopositive for CK7 and featured byELOC and/orTSC/mTOR gene mutations. In the 2022 WHO classification,ELOC mutated RCC is classified as a molecularly defined RCCs as an individual renal entity. However, there are limited descriptions ofTSC/mTOR alterations in RCC FMS. Herein, we reported a case of 28-year-old woman with RCC FMS with intactELOC andTSC/mTOR genes butASXL1 mutation. The tumor cells were positive for mTOR expression. This case may indicate that altered mTOR expression, but not limited to mutatedTSC/mTOR gene, that participates in the pathogenesis of RCC FMS.
Source: Virchows Archiv - Category: Pathology Source Type: research