diagnosis - DermTech

sni

Hi All, A skin lesion developed a month ago. I had to wait for Dermatology appointment so I went for DermTech (non invasive diagnosis). The result came negative. A week later when I went to see dermatology doctor, he was asking be to do a biopsy to be sure. Nothing has changed during last one week. The lesion is flat and no crusting or bleeding. Not sure if I need to go for a biopsy. Any suggestion?