TY - JOUR
T1 - p16 immunostaining in cytology specimens
T2 - its application, expression, interpretation, and challenges
AU - Ribeiro, Efrain A.
AU - Maleki, Zahra
N1 - Publisher Copyright:
© 2020 American Society of Cytopathology
PY - 2021/7/1
Y1 - 2021/7/1
N2 - Introduction: p16 immunostaining is considered as a surrogate marker for human papillomavirus (HPV)-related head and neck squamous cell carcinomas (HNSCC). Herein, the utility of p16 is evaluated in cytology specimens. Material and methods: The electronic data of a large academic institution was searched for cytology cases accompanied by p16 (2014-2018). Cases were categorized based on body sites. P16 staining was quantified (negative [0%], focal/patchy, or diffusely positive [>70%]). HPV testing was correlated where available. Results: A total of 372 cases were included (male:female, 239:133). The largest differences in application of p16 between men and women were in head/neck cases (209 versus 59) and the abdominal cases (1 versus 33), respectively. p16 diffuse staining is seen in most squamous cell carcinomas, small cell carcinomas, and gynecologic serous carcinomas. p16 expression was patchy or negative in most adenocarcinoma, neuroendocrine carcinoma, spindle cell neoplasms, and benign conditions. HPV testing was done on 217 cases including 138 cases with strong p16 (127 HPV+/11 HPV−), 20 cases with focal/patchy P16 staining (6 HPV+/14 HPV−) and 59 cases with negative p16 staining (3 HPV+/56 HPV−). Conclusions: Diffuse p16 staining aids in the diagnosis of HPV-related carcinomas, particularly HPV-related HNSCC, across the body and according to sex. In contrast, focal/patchy p16 staining does not correlate with HPV status across various body sites. In conclusion, intensity of p16 matters and should be correlated with cytomorphology, clinical history, and ancillary studies (eg, p40 immunostaining) for an accurate diagnosis and preventing diagnostic pitfalls.
AB - Introduction: p16 immunostaining is considered as a surrogate marker for human papillomavirus (HPV)-related head and neck squamous cell carcinomas (HNSCC). Herein, the utility of p16 is evaluated in cytology specimens. Material and methods: The electronic data of a large academic institution was searched for cytology cases accompanied by p16 (2014-2018). Cases were categorized based on body sites. P16 staining was quantified (negative [0%], focal/patchy, or diffusely positive [>70%]). HPV testing was correlated where available. Results: A total of 372 cases were included (male:female, 239:133). The largest differences in application of p16 between men and women were in head/neck cases (209 versus 59) and the abdominal cases (1 versus 33), respectively. p16 diffuse staining is seen in most squamous cell carcinomas, small cell carcinomas, and gynecologic serous carcinomas. p16 expression was patchy or negative in most adenocarcinoma, neuroendocrine carcinoma, spindle cell neoplasms, and benign conditions. HPV testing was done on 217 cases including 138 cases with strong p16 (127 HPV+/11 HPV−), 20 cases with focal/patchy P16 staining (6 HPV+/14 HPV−) and 59 cases with negative p16 staining (3 HPV+/56 HPV−). Conclusions: Diffuse p16 staining aids in the diagnosis of HPV-related carcinomas, particularly HPV-related HNSCC, across the body and according to sex. In contrast, focal/patchy p16 staining does not correlate with HPV status across various body sites. In conclusion, intensity of p16 matters and should be correlated with cytomorphology, clinical history, and ancillary studies (eg, p40 immunostaining) for an accurate diagnosis and preventing diagnostic pitfalls.
KW - Cytology
KW - Cytopathology
KW - HPV-Related head and neck squamous cell carcinoma
KW - Human papillomavirus (HPV)
KW - Serous carcinoma
KW - Small cell carcinoma
KW - p16 immunostain
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U2 - 10.1016/j.jasc.2020.12.003
DO - 10.1016/j.jasc.2020.12.003
M3 - Article
C2 - 33422456
AN - SCOPUS:85099154148
SN - 2213-2945
VL - 10
SP - 414
EP - 422
JO - Journal of the American Society of Cytopathology
JF - Journal of the American Society of Cytopathology
IS - 4
ER -