[Low-grade eosinophilic unclassified renal cell carcinoma, a recently proposed entity in the spectrum of eosinophilic renal cells tumors: Report of one case and discussion]. / Le carcinome rénal inclassé de bas grade à cellules éosinophiles, une entité récemment proposée dans le spectre des tumeurs rénales à cellules éosinophiles : étude d'un cas et discussion.

Low-grade eosinophilic unclassified renal cell carcinoma is a rare kidney tumor recently described, not included in the WHO classification, which is very close to oncocytoma. It is unknown to most pathologists and clinicians. From a histopathological point of view, this tumor is composed of oncocytic cells arranged in a diffuse and solid pattern, without cell nests, that makes it possible to differentiate it from oncocytoma, and expresses cytokeratin 7 (CK7) heterogeneously. We report a case with a cranial vault metastasis, and present the features to differentiate this entity from oncocytoma. Furthemore, we discuss about unclassified renal cell carcinomas with oncocytic cells.

The density of Tbet+ tumor-infiltrating T lymphocytes reflects an effective and druggable preexisting adaptive antitumor immune response in colorectal cancer, irrespective of the microsatellite status.

Purpose: The recent success of anti-PD1 antibody in metastatic colorectal cancer (CRC) patients with microsatellite instability (MSI), known to be associated with an upregulated Th1/Tc1 gene signature, provides new promising therapeutic strategies. However, the partial objective response highlights a crucial need for relevant, easily evaluable, predictive biomarkers. Here we explore whether in situ assessment of Tbet+ tumor infiltrating lymphocytes (TILs) reflects a pre-existing functional antitumor Th1/Tc1/IFNγ response, in relation with clinicopathological features, microsatellite status and expression of immunoregulatory molecules (PD1, PDL1, IDO-1). Methodology: In two independent cohorts of CRC (retrospective n = 80; prospective n = 27) we assessed TILs density (CD3, Tbet, PD1) and expression profile of PDL1 and IDO-1 by immunohistochemistry/image analysis. Furthermore, the prospective cohort allowed to perform ex vivo CRC explant cultures and measure by Elisa the IFNγ response, at baseline and upon anti-PD1 treatment. Results: The density of Tbet+ TILs was significantly higher in MSI CRC, especially in the medullary subtype but also in a subgroup of MSS (microsatellite stable), and positively correlated with PD1 and PDL1 expression, but not with IDO-1. Finally, a high number of Tbet+ TILs was associated with a favorable overall survival. These Tbet+ TILs were functional as their density positively correlated with basal IFNγ levels. In addition, the combined score of Tbet+ PD1+ TILs coupled with IDO-1 expression predicted the magnitude of the IFNγ response upon anti-PD1. Conclusion: Altogether, immunohistochemical quantification of Tbet+ TILs is a reliable and accurate tool to recapitulate a preexisting Th1/Tc1/IFNγ antitumor response that can be reinvigorated by anti-PD1 treatment.