Abstract

Most renal cell carcinomas (RCCs) are clear cell RCCs, the second most common being papillary RCCs (PRCCs). PRCCs are sub classified as type 1, type 2A, type 2B and mixed type. Pure type 2A PRCCs are estimated to account for only approximately 1-2% of malignant tumors of the kidney. In this paper, we show a case of an exophytic type 2A PRCC with massive necrosis arising in an 80-year-old male. The tumor, which measured 45mm in diameter and showed exophytic growth, was in the left kidney. The tumor was resected by a partial resection of the kidney and was found to be mainly necrotic, while the viable part showed papillary growth. There were small cuboidal cells with eosinophilic cytoplasm covering thin papillae with a single line of uniform small-to-medium sized nuclei and small nucleoli. The tumor was also positive for cytokeratin 7. Following Yang et al, we diagnosed the tumor as a type 2A PRCC.

Conclusion: Type 2 PRCCs should be clearly differentially diagnosed into type 2A or 2B, since the prognosis is different between these two types.

Keywords: Papillary renal cell carcinoma; Type 2A; Exophytic growth; Massive necrosis