Aims: Several entities have been individualized recently within the family of renal neoplasms with papillary features. Clear cell papillary renal cell carcinoma (CCPRCC) was first described in patients with end-stage renal disease, but is also observed in patients with normal renal function. The objective of this study was to document the clinicopathological and immunohistochemical characteristics of CCPRCC, with a special emphasis on cyclin D1 expression.
Methods and results: The patients were 25 men and 17 women, mean age 60.7 years. Seventeen patients had a chronic renal disease. All tumours were stage pT1, with a mean diameter of 2 cm. Six tumours were multifocal. Tumours cells were mainly cuboidal, with clear cytoplasm and low-grade nuclei apically aligned. In all cases, Fuhrman nuclear grade was one or two. No necrosis or vascular invasion was seen. During follow-up (10-72 months), no metastasis or death related to the disease was observed. Immunohistochemistry showed strong and diffuse cytokeratin 7 immunoreactivity in all cases, but no labelling for AMACR or TFE3. There was diffuse nuclear cyclin D1 immunoreactivity in 83% of cases.
Conclusion: CCPRCC is now a well-characterized entity. This tumour is an indolent and very low-grade neoplasm. Here we report the first study, to our knowledge, demonstrating the overexpression of cyclin D1 immunostaining by this tumour.
Keywords: clear cell papillary carcinoma; cyclin D1; immunohistochemistry; kidney.
© 2013 John Wiley & Sons Ltd.