The unusual nested carcinoma of the renal pelvis.

Invasive urothelial carcinoma has a potential to show divergent differentiation. Several uncommon morphological variants have been described in the recent past. One such rare type is the nested variant of urothelial carcinoma. Most of the published reports depict occurrence of this variant in the urinary bladder. We report an unusual presentation of this uncommon entity in the renal pelvis of a 54-year-old lady who presented with widespread skeletal metastases without any urinary symptoms.