Stations alter miniscule cases (7)
I believe the answer is:
termini
'stations' is the definition.
(terminus is a kind of station)
'alter miniscule cases' is the wordplay.
'cases' indicates the answer is hidden within the clue.
'TERMINI' is hidden in the letters of 'alter miniscule'.
(Other definitions for termini that I've seen before include "Stops" , "End-of-line stations" , "Rail, bus stations" , "Paddington, Waterloo, etc" , "Railway ends" .)