Article Text
Abstract
Introduction Human papilloma virus (HPV) associated vulval squamous cell carcinoma (VSCC) has better prognosis than HPV-independent VSCC. Ancillary tests are necessary as morphology alone is unreliable in differentiating these.
Methods We analysed 18 VSCC cases by comparing their morphology with three ancillary tests performed to identify the HPV status.
Results Basaloid/warty type VSCC considered to be HPV-associated; accounted for 6/18 cases (33.3%). Of these, 5 cases (83.3%) showed block p16 positivity and 3 cases (50%) had a positive HPV genotyping result.
Keratinising VSCC considered to be HPV-independent; accounted for 11/18 cases (61.1%). Amongst these, 3 cases (27.3%) showed block 16 positivity and 2 cases (18.2%) had positive HPV genotyping results. In one case, the VSCC was too small to assess the morphology.
Usual type VIN considered to be HPV-associated, was seen in 11/18 cases (61.1%). Of these, 8 cases (72.7%) showed block p16 positivity and 6 cases (54.5%) had a positive HPV genotyping result.
Differentiated VIN considered to be HPV-independent, was seen in 4/18 cases (22.2%). Amongst these, 0 cases (0%) showed block p16 positivity and 0 cases (0%) had a positive HPV genotyping result.
HPV genotyping detected high risk HPV in 6/18 cases (33.3%) and all these cases showed block p16 positivity.
In 3/9 cases (33.3%), with block p16 positivity, genotyping did not reveal any HPV.
HPV immunohistochemistry was negative in all cases.
Conclusion Our study illustrates that in the absence of a gold standard test for HPV, p16 immunohistochemistry and HPV genotyping are complimentary ancillary tests in VSCC.