Test Characteristics of Specific p16 Clones in the Detection of High-grade Squamous Intraepithelial Lesions (HSIL):

Histomorphology based prediction of p16 immunopositivity and p16/HPV DNA co-positivity in oral squamous cell carcinoma

The histomorphological features predictive of p16 and human papilloma virus (HPV DNA) positivity in oropharyngeal carcinoma have been a matter of much debate. However, only few studies have been done on oral squamous cell carcinoma (OSCC) to correlate the histomorphological features with p16 and HPV DNA positivity. Oral squamous cell carcinoma has distinct etiopathogenesis, treatment and prognosis as compared to oropharyngeal carcinomas. A total of 800 oral squamous cell carcinoma biopsy cases were evaluated for features suggestive of HPV infection like basaloid appearance, absence of stromal reaction, nests and lobules of tumor cells with pushing borders, central necrosis, lympho-epithelial morphology, koilocytes, and non-keratinizing or hybrid morphology. Immunohistochemistry was performed for p16 expression (E6H4 clone, CINtec histology, Roche diagnostics). The cases which showed 2+/3+ (from moderate to high intensity) staining with >75 % cells were considered as p16 immunopositive. All the p16 immunopositive cases were subjected to real-time PCR (polymerase chain reaction) for HPV DNA detection to confirm HPV positivity. A total of 139 (17.37 %) OSCC cases were p16 immunopositive and out of these 104 (104/139, 74.8 %) cases showed HPV-DNA PCR positivity. None of the features were found to be predictive on multivariate logistic regression analysis. However, on bivariable analysis, nest/lobule with pushing border was the only histopathological feature which had a significant correlation with p16 immunopositivity (P value = 0.0001) and p16 and HPV DNA copositivity (P value = 0.0001). (Fisher's exact test -two tailed). To conclude-morphology is not really predictive of HPV positivity in OSCC cases. Only one feature- nests and lobule with pushing border is suggestive on bivariable analysis.

2020 WHO Classification of Female Genital Tumors

The 2020 WHO classification is focused on the distinction between HPV-associated and HPV-independent squamous cell carcinoma of the lower female genital organs. Differentiating according to HPV association does not replace the process of grading; however, the WHO classification does not recommend any specific grading system. VIN are also differentiated according to whether they are HPV(p16)-associated. HPV-independent adenocarcinoma (AC) of the cervix uteri has an unfavorable prognosis. Immunohistochemical p16 expression is considered to be a surrogate marker for HPV association. HPV-associated AC of the cervix uteri is determined using the prognostically relevant Silva pattern.

Anogenital High-Grade Squamous Intraepithelial Lesion Comorbid With Vulvar Lichen Sclerosus and Lichen Planus

OBJECTIVE

The aim of the study was to describe the clinicopathologic features of vulvovaginal or anal high-grade squamous intraepithelial lesion (HSIL) comorbid with lichen sclerosus and/or lichen planus (LS/LP).

METHODS

The local pathology database identified 37 consecutive cases from 2007 to 2019 of vulvar, vaginal, or anal HSIL among women who had a histopathologic diagnosis of vulvar LS/LP. Cases had p16 and p53 immunoperoxidase stains. Clinical data included age, relative location of HSIL and LS/LP, immune-modifying conditions, tobacco use, treatment type, and follow-up. Histopathologic data included HSIL morphology categorized as warty-basaloid or keratinizing, p16 and p53 patterns within HSIL, and features of LS/LP.

RESULTS

The mean age was 69 years with a median follow-up up 42 months. Lichen sclerosus, alone or in combination with LP, was the comorbid dermatosis in 89%. Lichen sclerosus/lichen planus was overlapping or adjacent to HSIL in two-thirds of cases and located separately in the remainder. Rates of tobacco use and immunologic dysfunction were each 40%. In cases of co-located LS and HSIL, sclerosis was absent under the neoplasia in 57%. Twenty-four percent of HSIL cases showed keratinizing morphology; block-positive p16 and suprabasilar-dominant p53 helped distinguish HSIL from human papillomavirus-independent neoplasia.

CONCLUSIONS

Histopathologic identification of comorbid HSIL and LS/LP may be challenging because of keratinizing morphology and loss of diagnostic features of LS. Clinicopathologic correlation and use of p16 and p53 are essential to achieve an accurate diagnosis and enact disease-specific management plans.

Clinicopathologic Diagnostic Criteria for Vulvar Lichen Planus

OBJECTIVE

The aim of the study was to describe the clinical and histopathologic features required for a clinicopathologic diagnosis of vulvar lichen planus (LP), which is divided into 3 types: erosive, classic, and hypertrophic.

MATERIALS AND METHODS

The International Society of the Study of Vulvovaginal Diseases tasked the Difficult Pathologic Diagnoses committee with development of a consensus document for the clinicopathologic diagnosis of vulvar LP, lichen sclerosus, and differentiated vulvar intraepithelial neoplasia. The LP subgroup reviewed the literature and formulated diagnostic criteria, then approved by the International Society of the Study of Vulvovaginal Diseases membership.

RESULTS

The clinicopathologic diagnosis of erosive LP incorporates 5 criteria: (a) a well-demarcated, glazed red macule or patch at labia minora, vestibule, and/or vagina, (b) disease affects hairless skin, mucocutaneous junction, and/or nonkeratinized squamous epithelium, (c) evidence of basal layer damage, categorized as degenerative or regenerative, (d) a closely applied band-like lymphocytic infiltrate, and (e) absent subepithelial sclerosis. The clinicopathologic diagnoses of classic and hypertrophic LP each require a characteristic clinical appearance accompanied by hyperkeratosis, hypergranulosis, acanthosis, basal layer degeneration, a closely applied lymphocytic infiltrate, and absent dermal sclerosis, with hypertrophic LP showing marked epithelial abnormality compared with classic LP.

CONCLUSIONS

Clinicopathological correlation yields the most reliable diagnosis of vulvar LP. Disease appearance overlaps with other physiologic, dermatologic, infectious, and neoplastic entities; a low threshold for biopsy at all morphologically distinct areas is recommended. Use of the histopathologic criteria described in this document may reduce the nondiagnostic biopsy rate for clinically diagnosed LP.

Diagnostic Criteria for Differentiated Vulvar Intraepithelial Neoplasia and Vulvar Aberrant Maturation

OBJECTIVE

The aim of the study was to describe the features required for diagnosis of differentiated vulvar intraepithelial neoplasia (dVIN) and vulvar aberrant maturation (VAM).

MATERIALS AND METHODS

The International Society of the Study of Vulvovaginal Diseases tasked the difficult pathologic diagnoses committee to develop consensus recommendations for clinicopathologic diagnosis of vulvar lichen planus, lichen sclerosus, and dVIN. The dVIN subgroup reviewed the literature and formulated diagnostic criteria that were reviewed by the committee and then approved by the International Society of the Study of Vulvovaginal Diseases membership.

RESULTS

Differentiated vulvar intraepithelial neoplasia is the immediate precursor of human papillomavirus (HPV)-independent vulvar squamous cell carcinoma and shows a spectrum of clinical and microscopic appearances, some overlapping with HPV-related neoplasia. The histopathologic definition of dVIN is basal atypia combined with negative or nonblock-positive p16 and basal overexpressed, aberrant negative, or wild-type p53. The most common pattern of dVIN is keratinizing with acanthosis, aberrant rete ridge pattern, and premature maturation. The morphologic spectrum of keratinizing dVIN includes hypertrophic, atrophic, acantholytic, and subtle forms. A few dVIN cases are nonkeratinizing, with basaloid cells replacing more than 60% of epithelium. Vulvar aberrant maturation is an umbrella term for lesions with aberrant maturation that arise out of lichenoid dermatitis and lack the basal atypia required for dVIN.

CONCLUSIONS

Evaluation of women at risk for dVIN and VAM requires a collaborative approach by clinicians and pathologists experienced in vulvar disorders. Close surveillance of women with lichen sclerosus and use of these recommendations may assist in prevention of HPV-independent squamous cell carcinoma through detection and treatment of dVIN and VAM.

Are Histomorphological Features Predictive of p16 Immunopositivity Different for Oral and Oropharyngeal Squamous Cell Carcinoma?

Evidence from current studies show that squamous cell carcinomas at oral and oropharyngeal sites are distinct and unique, with their own separate etiopathogenesis, treatment, and prognosis. The aim of this work is to correlate p16 immunohistochemical expression with histomorphological features suggestive of HPV infection in oral and oropharyngeal squamous cell carcinoma. A total of 50 consecutive biopsy cases of oral squamous cell carcinoma (OSCC) and 50 consecutive biopsy cases of oropharyngeal squamous cell carcinoma (OPSCC) were evaluated for features suggestive of HPV infection like focal basaloid appearance, nests, and lobules of tumor cells with pushing borders, absence of stromal reaction, central necrosis, focal lymphoepithelial morphology, presence of koilocytes, and non-keratinizing or hybrid morphology. Immunostaining was performed using p16 monoclonal antibody (clone mouse 16P04). Only cases showing a moderate (2+) to high intensity (3+) staining in more than 75% cells were taken as p16 immunopositive. The histological features were correlated with p16 immunopositivity. A total of 18/50 (36%) cases of oral squamous cell carcinoma and 27/50 (54%) cases of oropharyngeal squamous cell carcinoma were p16 immunopositive. On statistical analysis, only nests/lobules with pushing borders were found to have a significant correlation with p16 immunopositivity (P value = 0.0012) for OSCC cases. For OPSCC cases, four histological features namely nests and lobules with pushing borders (P value = 0.0001), focal basaloid appearance (P value = 0.0041), lymphoepithelial morphology (P value = 0.0029), and non-keratinizing/hybrid morphology (P value = 0.0141) had a significant correlation with p16 immunopositivity. Histomorphological features are more helpful in predicting p16 immunopositivity in OPSCC than OSCC.

Cervical intraepithelial neoplasia in women who had vaccination against HPV

OBJECTIVE

To investigate the characteristics of women developing cervical intraepithelial neoplasia who had had a vaccination against human papillomavirus (HPV).

METHODS

A retrospective cohort study was carried out of women diagnosed with moderate or severe cervical dysplasia (CIN2+) in four Italian centers between 2015 and 2017. All women included had had previous bivalent or quadrivalent vaccination against HPV.

RESULTS

The present study included 43 patients affected by CIN2+. The median age was 28 (range, 21-41) years. Ten (23.3%) patients did not have a diagnosis of specific HPV type(s) involved: high-risk HPV was detected in 7 (16.3%) women while HPV testing was negative in 3 (6.9%) women. Lesions related to HPV16 were found in two patients. HPV types covered by nonavalent vaccination were diagnosed in 27/33 (81.8%) women. HPV types not covered by nonavalent vaccination were diagnosed in 6 (18.2%) women. Co-infections are most commonly detected in women with HPVs other than those included in the nonavalent vaccination (P=0.024).

CONCLUSION

Cervical dysplasia occurring after HPV vaccination is a rare condition. Theoretically, nonavalent vaccination should improve protection against more than 80% of HPV-related lesions compared to other vaccines.

The Diagnostic Utility of p16 Immunostaining in Differentiating Cancer and HSIL from LSIL and Benign in Cervical Cells

Cervical liquid-based cytology plays an important role in the diagnosis of cervical squamous intraepithelial lesion (SIL). However, cytological evaluation alone has a relatively low sensitive. To overcome this problem, HPV DNA testing or HPV DNA combined with cytology has been applied. HPV DNA testing significantly improved the sensitivity, but the specificity is low, especially in cancer and high-grade SIL (HSIL) cases. The aim of this study was to evaluate the diagnostic utility of p16 overexpression in cervical cells of patients with HSIL and cancer. The expression of p16 was detected by immunostaining in liquid-based cells from cervical brushing in 278 patients which including: Cancer (n = 13), HSIL (n = 112), low-grade SIL (LSIL) (n = 45), and Benign (n = 108). The expression levels of p16 were significantly higher in the cancer and HSIL groups when compared with the LSIL and Benign groups (P < 0.01). The accurate diagnostic rates of cancer and HSIL were significantly increased by p16 immunostaining plus cytology than that by cytology alone (P < 0.01). The false negative or false positive of p16 immunostaining occurred with a unicellular pattern. With sensitivity of 96.0% and accuracy of 91.7%, the diagnostic performance of p16 immunostaining was much better than that of cytology alone with sensitivity of 36.0% and accuracy of 70.9% (P < 0.01). p16 immunostaining in cervical brushing cells may not only be used as an ancillary tool to cytological diagnosis of cervical neoplasia but also help to distinguish HSIL from LSIL and the triage of transient infection.