Renal tubular papillary
group in the urine specimen.
It is quite common for
normal urine to contain papillary groups of cells and these should not be
over-interpreted as low-grade transitional cell carcinoma.
Renal tubular epithelial
cells may appear as tubulo-papillary structures that may masquerade as a
low-grade urothelial neoplasm.
Some of these tubular
cells appear distinct from usual urothelial cells with minimal cytoplasm
and "bulging" nuclei.
Possibility of underlying
renal parenchymal disease should be considered when red blood cell casts
are present along with these tubulo-papillary clusters.