['Earlier this summer I had to have a biopsy of a suspicious mass, to determine if it was cancerous or not. There was a lot of waiting involved which made me very nervous.']
Oh, man!  That is my nightmare!  You must have been so worried!  Are you OK?
I was informed by my doctor that I had to have a biopsy of a suspicious mass. The whole process of waiting for the test and results caused a lot of anxiety.