Characterization of Intercalated Cell Markers KIT and in Chromophobe Renal Cell Carcinoma and Other Renal Neoplasms.

Chromophobe renal cell carcinoma (chromophobe RCC) is the third major subcategory of renal tumors after clear cell RCC and papillary RCC, accounting for approximately 5% of all RCC subtypes. Other oncocytic neoplasms seen commonly in surgical pathology practice include the eosinophilic variant of chromophobe RCC, renal oncocytoma, and low-grade oncocytic unclassified RCC. In our recent next-generation sequencing based study, we nominated a lineage-specific novel biomarker (long intergenic non-protein coding RNA 1187) which was found to be enriched in chromophobe RCC. Like KIT (cluster of differentiation 117; CD117), a clinically utilized chromophobe RCC related biomarker, is expressed in intercalated cells of the nephron. In this follow-up study, we performed KIT immunohistochemistry and RNA in situ hybridization (RNA-ISH) on a cohort of chromophobe RCC and other renal neoplasms, characterized the expression patterns, and quantified the expression signals of the two biomarkers in both primary and metastatic settings. , in comparison to KIT, exhibits stronger and more uniform expression within tumors while maintaining temporal and spatial consistency. also is devoid of intra-tumoral heterogeneous expression pattern, a phenomenon commonly noted with KIT. expression can augment the currently utilized KIT assay and help facilitate easy microscopic analyses in routine surgical pathology practice.