Which of the following is a common finding in renal atrophy?

Decreased renal size is a hallmark characteristic of renal atrophy. In this condition, the kidney shrinks due to the loss of nephrons and functional tissue, typically as a result of chronic injury or disease. As the kidney atrophies, its size diminishes, which can be observed during imaging studies such as ultrasound.

While the other options may appear relevant in a broader context of renal pathology, they do not specifically represent the defining feature of renal atrophy. For instance, thickening of the renal cortex might be associated with other diseases, such as hypertension or glomerulonephritis, rather than atrophy. Increased echogenicity can indicate conditions such as chronic renal disease or scarring, but again, it does not serve as a direct indicator of atrophy. The presence of cysts may be observed in various renal conditions, including polycystic kidney disease, but is not a common finding associated directly with atrophy. Thus, decreased renal size stands out as the primary and most specific finding in cases of renal atrophy.