Fig. 3: Histomorphological features of papillary renal neoplasm with reverse polarity, papillary renal cell carcinoma type 1 and papillary renal cell carcinoma type 2.

Papillary renal neoplasm with reverse polarity frequently exhibited a fibrous capsule with peritumoral lymphoid aggregation at lower power field (a). It revealed prominent papillary or tubulopapillary architecture (b), low-grade nuclei, inverted linear nuclear location (c, d), and hyalinized papillae (d). Papillary renal cell carcinoma type 1 disclosed single cell lining with low-grade nuclei (e) and papillary renal cell carcinoma type 2 showed abundant eosinophilic cytoplasm with high-grade nuclei (f).