Abnormal cells. Squamous cells line the junction on the cervix between the vaginal cells and the endometrial canal cells; pap smear screen for abnormal appearances in these cells as they indicate precursors to cervical cancer. Atypical means abnormal, so atypical squamous cells mean that the cells on the cervix are abnormal, but mildly abnormal, and not abnormal enough to classify as dysplasia.
Atypical cells. This answer on a pap smear means that there are abnormal cells that do not look bad enough to call dysplasia. Because you are less than 30, no hpv testing is recommended. The pap result should also say whether it favors high grade dysplasia or low grade dysplasia. If it favors hg dysplasia then you should have a colposcopy. If it favors low grade dysplasia, then you should have a repeat in 6 mos.