Dilatation (expansion beyond the normal dimension) of the cavity (lumen) of tubules of the kidney. The tubular cross section displays an attenuated brush border (apical PAS positivity greater than 10 percent of the normal expected height, but unequivocally less than normal expected height), resulting in an apparent increase in the size of lumen. [https://orcid.org/0000-0003-2356-950X, PMID:29537990]
