Sudden breask lump

Hello:  I discovered a large breast lump about a month ago and the doctor if recommending further investigation.  I am waiting for an appointment at the local hospital where I imagine they will do a mamogram (mammogram).  I am 46 years old, no family history of breat cancer.  The lump was initially very large and hard but not really painful.  I could even see the lump on some days.  After my period it didn't seem to be so close to the surface but I can still feel a large hard area when I press down it is on my left breas behind just above the nipple area.  I am pretty freaked out.  Can a cyst also fit this description?

[Cleveland Clinic]

Dear sunshine0531,  Yes a cyst can also fit this description however without further evaluation it is impossible to say for sure what this is.  You are doing the right thing getting this evaluated further - hopefully all will be well.