Hi Amarjit,
I see it a lot. I am not exactly sure but i think it is dystrophic calcification from tenocyte death. ie from chronic stress.
It is usually asymptomatic so it makes no sense that it is hydroxyapatite or gout (monosodium urate) crystal deposition.
I think it is a benign finding and simply suggests some athletic activity which has previously overloaded the tendon.
I would appreciate everyone else’s opinion on this,
Steve