Details
72 year-old female with a history of chronic kidney disease presenting with a 6 cm right renal mass on imaging.
The second most common variant of renal cell carcinoma (RCC) is the papillary variant. Papillary RCC typically presents in a manner similar to other RCCs, namely as an incidental imaging finding, or pain and hematuria - due to mass effect - if it reaches a large size. Papillary RCC has also been shown to be associated with end stage renal disease, and is the most likely of the RCCs to present bilaterally, though unifocal tumours still comprise the majority of these lesions.
On gross examination papillary RCCs look very similar to other types of RCC, presenting usually as a well circumscribed cortical mass with areas of hemorrhage and necrosis. Microscopically, papillary RCC is divided into type 1 and type 2 patterns, with type 2 conveying a slightly worse prognosis. The type 1 pattern is a lesion with papillary growth whose fibrovascular cores are lined by a single layer of small cells with scant cytoplasm. In the type 2 pattern, fibrovascular cores are lined by a pseudostratified layer of cells with voluminous cytoplasm and prominent nucleoli. This this an example of type 1 papillary RCC, in which a focus demonstrates the presence of foamy macrophages within the fibrovascular core, a characteristic finding for this lesion.