Papillary renal cell carcinoma within a renal oncocytoma: case report of an incidental finding of a tumour within a tumour
- 1Department of Pathology and Laboratory Medicine, Toronto General Hospital, University Health Network, Toronto, Ontario, Canada
- 2Department of Surgery, Division of Urology, Princess Margaret Hospital, University Health Network, Toronto, Ontario, Canada
- 3Department of Pathology and Laboratory Medicine, Ontario Cancer Institute, University Health Network, Toronto, Ontario, Canada
- Correspondence to:
Dr A J Evans
Department of Pathology, 11th floor Eaton Wing, Toronto General Hospital, 200 Elizabeth Street, Toronto, ON, Canada M5G 2C4; andrew.evans @uhn.on.ca
- Accepted 27 June 2006
Abstract
The most common renal tumours are clear cell, papillary, chromophobe and collecting duct renal cell carcinomas (RCCs), and benign oncocytomas and angiomyolipomas. Tumours with hybrid features between some of these entities have been recognised; in particular, tumours with features of both chromophobe RCC and oncocytoma. Case reports describing one distinct type of primary renal tumour actually within another are very rare. The incidental finding of a papillary RCC located in an oncocytoma in a nephrectomy specimen from a 75-year-old man is described. Morphological criteria for each tumour type were completely satisfied and fluorescence in situ hybridisation detected the expected number of copies of chromosome 7 in the cells of each tumour type. The cells in the papillary tumour contained three copies, whereas the oncocytoma cells contained only two per nucleus. To our knowledge, this is the first report of a papillary RCC being identified within an oncocytoma.
Footnotes
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Competing interests: None declared.
