A colposcopy is a detailed examination of the cervix (entrance to the uterus) with a specially lit microscope (colposcope). As with a Pap smear, an instrument called a speculum is inserted into the vagina, and then the colposcope is inserted with its light directed on the cervix. A specialist will perform a colposcopy if a Pap smear has shown abnormal or cancerous cells on the cervix. During the colposcopy further samples (biopsies) are usually removed and examined in the lab so the doctor can get a more clear idea of the extent of the abnormal cells.