mammo and US results

hi i got my mammo and US results.mammo was clear.but they found a .2cm cyst in my US.btw way my 1st US which was 3 weeks before my 2nd one showed the cyst was 1cm.now it became smaller.maybe its bec my 1st US was done a week before my period and the second one was done a week after my period.i ask if i need a biopsy.the dr.said no need bec.the cyst is fluid filled.he said not to worry and just come back after a yr. for mammo and US.shouldnt i really not worry anymore?and no need really for biopsy?thank u in advance

[Cleveland Clinic]

Dear angie_gando:  A cyst is by definition benign.  It is a fluid filled structure.  There is no reason to aspirate or remove them unless they are causing discomfort.