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Grading of atypia in genital skin lesions: routine microscopic evaluation and use of p16 immunostaining
Author(s) -
Ezaldein Harib,
Lott Jason P.,
McNiff Jennifer M.,
Hui Pei,
Buza Natalia,
Ko Christine J.
Publication year - 2015
Publication title -
journal of cutaneous pathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.597
H-Index - 75
eISSN - 1600-0560
pISSN - 0303-6987
DOI - 10.1111/cup.12525
Subject(s) - immunostaining , atypia , pathology , medicine , dysplasia , staining , grading (engineering) , immunohistochemistry , biology , ecology
Background p16 immunostaining has been used to aid and improve the histopathologic evaluation of equivocal cervical lesions with associated low‐grade or high‐grade dysplasia. However, the utility of p16 immunostaining in the diagnosis of atypical genital skin lesions remains debatable. Methods We conducted a cross‐sectional study of genital skin lesions with varying degrees of atypia. Four pathologists assessed lesional atypia and interpreted hematoxylin and eosin (H&E) staining and p16 immunostaining without knowledge of original diagnosis. Our primary outcomes were diagnostic agreement and test performance of p16 immunostaining compared to consensus H&E diagnosis. Results Our sample was comprised of 23 cases of atypical genital skin lesions. p16 immunostaining was negative in all cases of reactive atypia (n = 3) and the majority (n = 7 of 8; 88%) of low‐grade squamous intraepithelial lesions ( LSILs ). The majority (n = 10 of 12; 83%) of high‐grade squamous intraepithelial lesions ( HSIL ) were p16 positive. Diagnostic agreement for histopathologic assessment using H&E staining was moderate (kappa = 0.44), while inter‐observer agreement of p16 immunostaining was excellent (kappa = 0.87). Compared to consensus diagnosis using H&E staining, p16 immunostaining performed well (sensitivity 83.3%; specificity 90.9%). Conclusions p16 immunostaining may be a useful adjunctive marker for assessing dysplasia in genital skin lesions and increasing diagnostic agreement among pathologists.