Chromophobe renal cell carcinoma (ChRCC) accounts for 5% to 7% of all renal cell carcinomas. It was thought for many years that ChRCC exhibits a hypodiploid genome. Recent studies using advanced molecular genetics techniques have shown more complex and heterogenous pattern with frequent chromosomal gains. Historically, multiple losses of chromosomes 1, 2, 6, 10, 13, 17, and 21 have been considered a genetic hallmark of ChRCC, both for classic and eosinophilic ChRCC variants. In the last 2 decades, multiple chromosomal gains in ChRCCs have also been documented, depicting a considerably broader genetic spectrum than previously thought. Studies of rare morphologic variants including ChRCC with pigmented microcystic adenomatoid/multicystic growth, ChRCC with neuroendocrine differentiation, ChRCC with papillary architecture, and renal oncocytoma-like variants also showed variable chromosomal numerical aberrations, including multiple losses (common), gains (less common), or chromosomal changes overlapping with renal oncocytoma. Although not the focus of the review, The Cancer Genome Atlas (TCGA) data in ChRCC show TP53, PTEN, and CDKN2A to be the most mutated genes. Given the complexity of molecular genetic alterations in ChRCC, this review analyzed the existing published data, aiming to present a comprehensive up-to-date survey of the chromosomal abnormalities in classic ChRCC and its variants. The potential role of chromosomal numerical aberrations in the differential diagnostic evaluation may be limited, potentially owing to its high variability.
Advances in anatomic pathology. 2020 Oct 05 [Epub ahead of print]
Reza Alaghehbandan, Kiril Trpkov, Maria Tretiakova, Ana S Luis, Joanna D Rogala, Ondrej Hes
Department of Pathology, Faculty of Medicine, Royal Columbian Hospital, University of British Columbia, Vancouver, BC., Department of Pathology and Laboratory Medicine, University of Calgary, Calgary, AB, Canada., Department of Pathology, University of Washington, Seattle, WA., Department of Pathology, Portuguese Institute of Oncology of Porto Francisco Gentil, Porto, Portugal., Department of Pathology, Charles University in Prague, Faculty of Medicine and University Hospital in Plzen, Plzen, Czech Republic.