Editing AUA: Stone Surgery (2016) (section)

=== Asymptomatic, non-obstructing caliceal stones ===
* '''Active surveillance may be offered'''
** Observation of asymptomatic, non-obstructing caliceal stones is appropriate as long as the patient is counseled about the risk of stone growth, passage, and pain.
** '''There is conflicting data on the natural history of asymptomatic renal stones'''
*** '''≈50% of asymptomatic stones will progress, a much smaller percentage will require surgical intervention.'''
**** Lower pole stone location and isolated stone ≥ 4 mm were associated with a higher likelihood of failing observation.
** '''Treatment of asymptomatic, non-obstructing caliceal stones should be considered in:'''
**# '''Cases of associated infection'''
**# '''Vocational reasons (e.g. airline pilots, military)'''
**# '''Poor access to medical care'''
** If observation is chosen for asymptomatic, non-obstructing caliceal stones, '''follow-up imaging studies to assess for stone growth or new stone formation is recommended'''. Dietary modifications and medical therapy may be considered, especially if new stone formation occurs