Which of the following casts indicate extreme urinary stasis or chronic renal failure?

Waxy casts are indicative of extreme urinary stasis or chronic renal failure because they are formed from the degeneration of cellular casts and represent a long period of renal tubular stasis. These casts are typically broader and have a more homogenous and glassy appearance compared to other types of casts. The presence of waxy casts in urine suggests that the kidneys are not functioning optimally, and they are often associated with significant underlying kidney pathology, including chronic kidney disease.

In contrast, hyaline casts are generally considered benign and can be noted in a variety of conditions, often in concentrated urine without much clinical significance. Cellular casts, such as red blood cell casts or white blood cell casts, may indicate acute kidney injury or glomerulonephritis, but they are not specifically linked to chronic renal failure or stasis. Granular casts are more common and can represent various conditions, including acute tubular injury, but their presence alone doesn’t imply long-standing renal issues as strongly as waxy casts do.