Papillary Renal Cell Carcinoma with Sarcomatoid Differentiation in a Native Kidney of Transplant Recipient: A Case Report and Review of Literature.

Renal cell carcinoma (RCC) developing in a transplant recipient is about 5-20 times higher than the general population. It is more common in native kidneys than graft kidney, and incidence varies between 0.3% and 4.8%. Clear cell and papillary types are more frequently reported. Most RCC of allograft recipient is usually low-grade with favorable prognosis. We present a case of papillary RCC with sarcomatoid differentiation (SD) in a native kidney of renal transplant (RT) recipient. The coexistence of sarcomatoid variant with papillary RCC, as in our case, makes it a high grade (WHO/ISUP grade 4) and portends a poor prognosis. Relative aggressiveness and rarity of this variant histology in transplant recipients prompted us to report this case and carry out an extensive search of the available literature.