Routine Use of p16 Aids the Detection of High Grade Squamous Intraepithelial Lesions in Endocervical Curettage Specimens
Akeesha A Shah, Susanne K Jeffus, Zimin Zhao, Harriet Scruggs, Edward B Stelow. University of Virginia, Charlottesville, VA
Background: The utility of endocervical curettage (ECC) in the diagnosis of cervical neoplasia is controversial as studies have shown that it is fraught with false positive and negative results as well as significant diagnostic interobserver variability. p16 has been shown to be useful in detection of cervical high grade squamous intraepithelial lesions (HSIL). We questioned whether p16 staining of ECCs in patients with antecedent ASC-H and HSIL Pap test would improve its diagnostic sensitivity.
Design: 58 consecutive ECCs that were previously diagnosed as negative for SIL in patients with antecedent ASC-H or HSIL Pap tests were retrieved. An H&E recut and immunohistochemistry for p16 were performed on all cases. A diagnosis of HSIL (CIN2/CIN3) was made if there was strong nuclear and cytoplasmic staining in cells with the appropriate cytomorphologic features. Follow-up results from Pap tests, biopsy procedures and HPV status were documented.
Results: HSIL was found in 20 ECCs (34%) originally interpreted as negative. Of these 20 cases, 9 had moderate-sized fragments of ectocervical epithelium with HSIL that was only seen on the recut H&E with supporting strong immunostaining with antibodies to p16. 11 cases had rare to occasional clusters or single atypical cells with strong immunoreactivity for p16 (Figure 1).
The 38 negative ECCs were either completely negative for p16 or demonstrated focal staining of non-dysplastic epithelium (e.g. tubal metaplasia). When available, HPV status for ECCs with HSIL was as follows: 8 positive, 2 negative. HPV status for negative ECCs was as follows: 15 positive, 11 negative. Follow-up was available for 26 patients and is summarized in Table 1.
|FOLLOW UP||ECC with HSIL||ECC NEGATIVE for HSIL|
|LSIL (CIN I)||0||0|
|HSIL (CIN II/III)||2||0|