I agree with all of you that it is a CIN3 with endocervical glandular involvement. I am not surprised at all for the cytologic diagnosis of LSIL, since HSIL is the most challenging diagnosis and easily to be missed in LBC, especially when cytologic preparation technology is poor. Another situation for missing HSIL is when you see lot of LSIL cells in a smear. The rule of thumb is whenever you make a diagnosis of LSIL, make sure your excitement is just focused on LSIL cells. Instead you should carefully search for HSIL and rule out co-existing HSIL before you make a diagnosis of LSIL.

Conceptually CIN3 and CIS are almost the same, although some pathologists still like to use CIS to emphasize the degree of dysplasia. In term of clinical management, it will be treated the same by LEEP or large loop excision of the transformation zone (LLETZ)-conization depending on if there is endocervical glandular involvement. The important line dividing the treatment strategies is whether there is invasion or not. Even focal microinvasion will trigger the hysterectomy procedure. Another important part is to examine if there is lymphovascular invasion. Although the presence of vascular invasion does not change the clinical stage, it does have influence of clinical management.