Anal intraepithelial neoplasia, AIN

Normal

Condyloma

AIN I

AIN II

AIN III

p16

spotty staining of more than 10% of squamous cells(staining in scattered cells at any level of the epithelium)

3/371

1/121

2/141

3/251

2/161

contiguous staining of more than 90% of squamous cells

1/37(staining in the one positive case was confined to the lower third of the epithelium)1

0/121

3/14(staining confined to the lower third of the epithelium)1

20/25(staining is seen in at least the lower two thirds of the epithelium)1

14/16(staining is seen in at least the lower two thirds of the epithelium)1

Ki67

<25% positive nuclei

35/371

7/121

6/141

3/251

1/161

25-50% positive nuclei

3/271

5/121

4/141

10/251

3/161

50-75% positive nuclei

4/141

7/251

7/161

75-100% positive nuclei

5/251

5/161