papanicolaou smear screening for detection of early precancerous changes of the cervix and referral for colposcopy and biopsy of areas of epithelium that are suspicious for intraepithelial neoplasia of the cervix , vagina , vulva , penis , or anus remain the cornerstones of genital tract and anal cancer prevention .
C0009417
colposcopy
C0042232
vagina