Classification According to Papanicolaou
| Classification | (Repeat) Advice |
| CLASS 0 | |
| No endocervical cells | Repeat during next cycle |
| Poor quality of smear | Repeat during next cycle |
| Too little material, poor fixation | Repeat during next cycle |
| CLASS I | |
| No abnormalities of the epithelial cells | Repeat after 5 years (if 2 times Pap I) |
| CLASS II | |
| Reactive stratified squamous, endocervix, endometrium epithelial cells or koilocytosis | Repeat after 6 months |
| Very marked inflammation | Repeat after treatment |
| Atrophy with atypical nuclei | Repeat after oestrogen course |
| Atypical endometrial epithelial cells | Repeat following discontinuation of oestrogen therapy |
| Other | Repeat after ½ year |
| CLASS IIIA | |
| Limited to moderate dysplasia of the stratified squamous and/or endocervical epithelial cells | Repeat after 3 months, possibly colposcopy examination; if persists, histological analysis |
| Atypical reserve cells | |
| Atypical endometrial epithelial cells | |
| CLASS IIIB | |
| Marked dysplasia of the stratified squamous and/or endocervical epithelial cells | Histological analysis |
| Highly atypical reserve cells | |
| Highly atypical endometrial epithelial cells | |
| CLASS IV | |
| Carcinoma in-situ | Histological analysis |
| CLASS V | |
| Invasive stratified squamous cell carcinoma | Histological analysis |
| Adenocarcinoma |
Further investigations: Tissue biopsy is taken from the abnormal tissue for histological analysis, i.e. a piece of tissue is examined as a whole (as opposed to the smear sample in which loose cells are spread on a slide and analysed – known as cytology). The histological assessment is conducted according to CIN-classification (cervical intraepithelial neoplasia).