Diagnosing cervical biopsies in adolescents: the use of p16 immunohistochemistry to improve reliability and reproducibility.

OBJECTIVE: To increase the specificity in diagnosing cervical biopsies in adolescents, we evaluated the use of p16 immunohistochemistry (IHC) as an adjuvant test in addition to hematoxylin and eosin (H&E).

MATERIALS AND METHODS: One hundred cervical histological tissues from adolescents were stained with routine H&E and monoclonal p16 (clone E6H4; dilution, 1:25; Dako). One gynecologic pathologist and 3 pediatric pathologists independently reviewed the cases, rendered diagnoses first by using H&E alone, and then added p16 IHC as an adjuvant marker. The interobserver agreement between the gynecologic pathologist and the pediatric pathologists was calculated using kappa statistics.

RESULTS: The agreement rates between the gynecologic pathologist and all 3 pediatric pathologists were fair (kappa = 0.39, 0.36, and 0.37) when only H&E sections were used, and were improved to moderate (kappa = 0.53, 0.44, and 0.50) after using p16 IHC in addition to H&E.

CONCLUSIONS: The evaluation of cervical intraepithelial neoplasia based solely on H&E-stained biopsies may lack interobserver reproducibility. The p16 IHC reduces the number of discrepancies and improves the rate of agreement among pathologists in diagnosing adolescent's cervical lesions. The improvement in the diagnosis of cervical biopsies has important implications in the treatment and follow-up of adolescent girls with abnormal cervical cytological diagnoses.