when positive smears have been obtained , cold-knife cone biopsy is indicated ( a ) whenever gross lesions are not visible on the ectocervix , ( b ) if carcinoma in situ is found in a biopsy of the external os , in order to determine the presence or absence of invasion , and ( c ) when there are repeated positive smears and biopsy of the portio has not shown the presence of malignancy .
C0007099
carcinoma in situ
C1706685
absence of invasion