Variation in nuclear size and PD-L2 positivity correlate with aggressive chromophobe renal cell carcinoma

Chromophobe renal cell carcinoma (CRCC) is not amenable to International Society for Urologic Pathology-endorsed nucleolar grading. Novel grading approaches were proposed, but the rarity of adverse pathology hampers their discriminatory value. We investigate simple linear micrometer measurements and a proposed immunostain in CRCCs. 32 patients' CRCCs were studied: 12 adverse cases (stage pT3, recurrence, or metastasis), 15 controls (stage ≤pT2, no recurrence or metastasis after >3 years), and 8 metastases (3 were paired with primary adverse cases). The ratio of greatest dimensions of largest and smallest nuclei, in each of 5 “worst” high-power fields, excluding those with degenerative features, was designated variation in nuclear size (VNS). Percent multinucleate cells (PMC) were also counted. Mouse anti PD-L2 monoclonal antibody immunostaining was performed. Mean VNS measured in adverse primary and control primary tumors were 3.7 ± 0.5 and 2.4 ± 0.4 respectively (P