p16 and Ki-67 immunostaining in atypical immature squamous metaplasia of the uterine cervix: correlation with human papillomavirus detection

Diagnostic Challenges during Inflammation and Cancer: Current Biomarkers and Future Perspectives in Navigating through the Minefield of Reactive versus Dysplastic and Cancerous Lesions in the Digestive System

In the setting of pronounced inflammation, changes in the epithelium may overlap with neoplasia, often rendering it impossible to establish a diagnosis with certainty in daily clinical practice. Here, we discuss the underlying molecular mechanisms driving tissue response during persistent inflammatory signaling along with the potential association with cancer in the gastrointestinal tract, pancreas, extrahepatic bile ducts, and liver. We highlight the histopathological challenges encountered in the diagnosis of chronic inflammation in routine practice and pinpoint tissue-based biomarkers that could complement morphology to differentiate reactive from dysplastic or cancerous lesions. We refer to the advantages and limitations of existing biomarkers employing immunohistochemistry and point to promising new markers, including the generation of novel antibodies targeting mutant proteins, miRNAs, and array assays. Advancements in experimental models, including mouse and 3D models, have improved our understanding of tissue response. The integration of digital pathology along with artificial intelligence may also complement routine visual inspections. Navigating through tissue responses in various chronic inflammatory contexts will help us develop novel and reliable biomarkers that will improve diagnostic decisions and ultimately patient treatment.

p16 Immunohistochemistry as a Screening Tool for Homozygous CDKN2A Deletions in CNS Tumors

The 2021 World Health Organization classification of tumors of the central nervous system emphasizes the significance of molecular parameters for an integrated diagnosis. Homozygous deletion of cyclin-dependent kinase inhibitor 2a (CDKN2A) has been associated with an adverse prognosis in IDH -mutant gliomas, supratentorial ependymomas, meningiomas, and MPNST. In this study, we examined the value of p16 protein immunohistochemistry as a rapid and cost-effective screening tool for a homozygous CDKN2A deletion. Genetic analyses for CDKN2A in 30 pleomorphic xanthoastrocytomas, 32 IDH -wild-type high-grade gliomas, 40 supratentorial ependymomas with ZFTA-RELA gene fusion, 21 IDH-mutant astrocytomas, and 24 meningiomas were performed mainly by a molecular inversion probe assay, a high-resolution, quantitative technology for the assessment of chromosomal copy number alterations. Immunohistochemistry for p16 proved to have a high positive predictive value (range 90% to 100%) and an overall low negative predictive value (range 22% to 93%) for a homozygous CDKN2A deletion. In a setting where molecular testing is limited for cost and time reasons, p16 immunohistochemistry serves as a useful and rapid screening tool for identifying cases that should be subjected to further molecular testing for CDKN2A deletions.

Invasive Squamous Cell Carcinoma of the Cervix: A Review of Morphological Appearances Encountered in Human Papillomavirus-associated and Papillomavirus-independent Tumors and Precursor Lesions

Cervical cancer is the fourth most common cancer among women globally. Historically, human papillomavirus (HPV) infection was considered necessary for the development of both precursor and invasive epithelial tumors of the cervix; however, studies in the last decade have shown that a significant proportion of cervical carcinomas are HPV-independent (HPVI). The 2020 World Health Organization (WHO) Classification of Female Genital Tumors separates both squamous cell carcinomas (SCCs) and endocervical adenocarcinomas (ECAs) by HPV status into HPV-associated (HPVA) and HPVI tumors. The classification further indicates that, in contrast to endocervical adenocarcinomas, HPVI and HPVA SCCs cannot be distinguished by morphological criteria alone and suggests that HPV testing or correlates thereof are required for correct classification. Moreover, while HPVA SCC precursor lesions (ie, high-grade squamous intraepithelial lesion) are well known and characterized, precursors to HPVI SCCs have only been described recently in a small number of cases. We studied 670 cases of SCCs from the International Squamous Cell Carcinoma Project (ISCCP) to analyze the reproducibility of recognition of invasive SCC growth patterns, presence of lymphovascular space invasion, tumor grade, and associations with patient outcomes. Consistent with previous studies, we found histologic growth patterns and tumor types had limited prognostic implications. In addition, we describe the wide morphologic spectrum of HPVA and HPVI SCCs and their precursor lesions, including tumor growth patterns, particular and peculiar morphologic features that can lead to differential diagnoses, and the role of ancillary studies in the diagnosis of these tumors.

Challenging lesions in cervical cytology: The elusive HSIL

Cervical cytology has been an integral part of cervical cancer screening since the mid-20th century with the implementation of screening protocols utilising Pap testing. During that time, cervical cancer has gone from the leading cause of cancer deaths in women to not even appearing in the top 10 causes of US cancer deaths. However, despite its long and widespread use, cervical cytology remains a diagnostically challenging area in the practice of cytopathology. Of particular importance for diagnosticians is the accurate diagnosis of high-grade squamous intraepithelial lesions (HSILs), given the significant risk of progression to invasive cervical cancer and the importance to patient management. Therefore, this review is presented in order to highlight the diagnostic features of HSIL, its various appearances, and important benign and neoplastic differential considerations with an emphasis on morphological clues that can aid in distinguishing between these different processes.

CIN grades possessing different HPV RNA location patterns and RNAscope is helpful tool for distinguishing squamous intraepithelial lesions in difficult cervical cases

BACKGROUND AND OBJECTIVES

The precise grading and characterization of cervical intraepithelial neoplasia (CIN) has been the focus of pathologists for a long time. This study aimed to explore known strategies for the grading of CINs.

METHODS

After routine H&E review, 85 lesions graded CIN 1, 2, or 3 were investigated primarily by HPV RNAscope to detect HR-HPV and LR-HPV, in combination with an HPV-DNA test and P16/Ki67 immunohistochemistry (IHC). Then, the 85 cases were divided into a control group (49 cases) and a test group (36 cases). The former consisted of cases with consistency between morphology, HPV DNA detection and P16/Ki67 IHC. We used them to evaluate HPV RNA distribution patterns in CINs of different grades. The latter were ambiguous cases in which pathologists could not confirm the diagnosis because of inconsistencies between morphology, HPV DNA detection and P16/Ki67 IHC. We reassessed them by comparison to the pattern in the control group.

RESULTS

The expression patterns of HPV mRNA signals were different in different CIN lesions. LSIL/CIN1 lesions were mostly expressed in superficial epithelium with diffuse clustered nuclear or cytoplasmic staining; HSIL/CIN2 were characterised by nuclear/cytoplasmic punctate or diffuse cluster nuclear staining in the mid-surface layer, and scattered nuclear/cytoplasmic punctate staining in basal and parabasal cells; whereas HSIL/CIN3 showed full-thickness nucleus/cytoplasmic scattered staining with a punctate pattern. According to the staining pattern, we corrected the diagnosis of 22 cases (22/36, 61.1%).

CONCLUSION

Because of its distinct location pattern, HPV RNAscope has obvious advantages over the HPV-DNA test, and combined with P16/Ki67 IHC, it can help pathologists correctly grade CIN. In addition, it can effectively discriminate true CIN from normal or CIN mimic lesions, such as immature squamous metaplasia, atrophy, and inflammatory/reactive changes. Therefore, HPV RNAscope is a valuable auxiliary diagnostic test to avoid the overtreatment and undertreatment of CIN lesions.

The Expression of Testin, Ki-67 and p16 in Cervical Cancer Diagnostics

Testin is a protein expressed in normal human tissues, being responsible, with other cytoskeleton proteins, for the proper functioning of cell−cell junction areas and focal adhesion plaques. It takes part in the regulation of actin filament changes during cell spreading and motility. Loss of heterozygosity in the testin-encoding gene results in altered protein expression in many malignancies, as partly described for cervical cancer. The aim of our study was the assessment of the immunohistochemical (IHC) expression of testin in cervical cancer and its analysis in regard to clinical data as well the expression of the Ki-67 antigen and p16 protein. Moreover, testin expression was assessed by Western blot (WB) in commercially available cell lines. The IHC analysis disclosed that the expression of testin inversely correlated with p16 (r = −0.2104, p < 0.0465) and Ki-67 expression (r = −0.2359, p < 0.0278). Moreover, weaker testin expression was observed in cancer cases vs. control ones (p < 0.0113). The WB analysis of testin expression in the cervical cancer cell lines corresponded to the IHC results and showed a weaker expression compared to that in the control cell line. When we compared the expression of testin in cervical cancer cell lines, we found a weaker expression in HPV-negative cell lines. In summary, we found that the intensity of testin expression and the number of positive cells inversely correlated with the expression of Ki-67 (a marker of proliferation) and p16 (a marker of cell cycle dysregulation). This study shows that the combined assessment of testin, Ki-67 and p16 expression may improve cervical cancer diagnostics.

Reclassification of atypical immature metaplasia of the uterine cervix by combination of nuclear features on hematoxylin and eosin-stained sections without auxiliary immunohistochemistry

Reclassification of endocervical atypical immature metaplasia (AIM) into reactive changes and neoplastic lesion is often challenging. We aimed to accurately reclassify AIM on hematoxylin and eosin (HE)-stained sections without auxiliary immunohistochemistry (IHC). A total of 133 AIM diagnosed by punch biopsy were reclassified by IHC for p16 and Ki-67 into high-grade squamous intraepithelial lesion (HSIL) or negative for intraepithelial lesion or malignancy or low-grade squamous intraepithelial lesion (NILM/LSIL) as a reference. Nuclear features significantly associated with HSIL on HE-stained sections were extracted by multivariate logistic regression analysis. Propensity score (PS) of HSIL was calculated in each case and cut-off was determined by receiver operation characteristic (ROC) curve analysis. As a result, AIM was reclassified into 104 NILM/LSIL and 29 HSIL by IHC. Compared with reference diagnosis, accuracy of pathologists' subjective diagnosis was 54.9% (kappa coefficient, 0.208). Three nuclear features on HE-stained sections, ie, nuclear enlargement with anisokaryosis, nuclear hyperchromasia, and mitosis, were significantly associated with HSIL. The ROC curve analyses revealed that PS and number of nuclear features were significant predictors of HSIL. Diagnostic accuracy of PS-based diagnosis was 76.7% (kappa, 0.447). When AIM with 2 or more of the 3 nuclear features was diagnosed with HSIL, diagnostic accuracy was 77.4% (kappa, 0.448). Nuclear feature-based diagnosis significantly improved diagnostic accuracy on HE-stained sections compared with subjective diagnosis and may be useful when IHC is not available. However, a considerable proportion of AIM would still remain misdiagnosed and IHC for p16 and Ki-67 should be mandatory for accurate reclassification.

Aggressive Cutaneous Squamous Cell Carcinomas Following Treatment for Graft-versus-Host Disease: A Case Report and Review of Risk Factors

A 19-year-old female with a history of pre-B cell acute lymphocytic leukemia (ALL) presented with two aggressive cutaneous squamous cell carcinomas (C-SCC) in the right hand. The patient was diagnosed with pre-B cell ALL at four years of age. She underwent chemotherapy with initial remission. However, recurrence of the pre-B cell ALL required an unrelated allogeneic cord hematopoietic stem cell transplant (alloHSCT). Post-transplant, the patient developed Graft-Versus-Host Disease (GVHD), which was treated with immunosuppressant therapy for six years until resolution. Fourteen years following the transplant, the patient developed a morbilliform drug eruption secondary to clindamycin. She consequently received prednisone treatment. During the treatment period, the patient developed a new ulcerated and tender nodule on the dorsal aspect of her right hand. Further histopathological biopsy confirmed the diagnosis of C-SCC, which required excision. Ten months following the excision, the patient developed an additional C-SCC nodule on the same right hand, separated by 2.6 cm from the prior C-SCC. She was referred for a ray resection procedure. This case illustrates a patient with multiple risk factors that may have contributed to the continued development of C-SCC. Such risk factors include: a prolonged course of immunosuppressant medications and voriconazole treatment. Additional research is needed to investigate the etiologies and risks of C-SCC development in patients who require a transplant and long-duration immunosuppressive therapy.

HIV-Associated Cancer Biomarkers: A Requirement for Early Diagnosis

Globally, HIV/AIDS and cancer are increasingly public health problems and continue to exist as comorbidities. The sub-Saharan African region has the largest number of HIV infections. Malignancies previously associated with HIV/AIDS, also known as the AIDS-defining cancers (ADCs) have been documented to decrease, while the non-AIDS defining cancer (NADCs) are on the rise. On the other hand, cancer is a highly heterogeneous disease and precision oncology as the most effective cancer therapy is gaining attraction. Among HIV-infected individuals, the increased risk for developing cancer is due to the immune system of the patient being suppressed, frequent coinfection with oncogenic viruses and an increase in risky behavior such as poor lifestyle. The core of personalised medicine for cancer depends on the discovery and the development of biomarkers. Biomarkers are specific and highly sensitive markers that reveal information that aid in leading to the diagnosis, prognosis and therapy of the disease. This review focuses mainly on the risk assessment, diagnostic, prognostic and therapeutic role of various cancer biomarkers in HIV-positive patients. A careful selection of sensitive and specific HIV-associated cancer biomarkers is required to identify patients at most risk of tumour development, thus improving the diagnosis and prognosis of the disease.

p16 Positive Histologically Bland Squamous Metaplasia of the Cervix: What does It Signify?

With increasing use of p16 immunohistochemistry (IHC) in diagnosis of premalignant lesions of cervix, we occasionally encounter p16 positivity in squamous metaplasia that lacks morphologic characteristics of "atypical squamous metaplasia" or of squamous intraepithelial lesion (SIL). Our study aims to investigate if transcriptionally active human papilloma virus (HPV) can be identified in such foci and if they have any relationship with squamo-columnar junction (SCJ) cells. Twenty-two cases of cervical specimens with at least a focus of p16 positive bland squamous metaplasia, were selected. HPV E6/E7 mRNA in situ hybridization followed by IHC for CK7 (SCJ biomarker), Ki67, and HPV16 E2, were performed. Follow-up information was obtained. Four cases were excluded due to insufficient tissue. Of the final 18 cases, HPV E6/E7 mRNA in situ hybridization was positive in all. Nine cases showed positivity in >50% cells and the epithelial thickness involved was ≥lower two-thirds in 13 cases. Of the further evaluable 15 cases, CK7 was positive in 14, Ki67 was positive in 10, and HPV16 E2 was negative in all. Concomitant high-grade squamous intraepithelial lesion was identified in 10 cases. On follow-up (duration: 1 to 19 mo), 6 patients showed histologic high-grade squamous intraepithelial lesion. Our study demonstrates that p16 positivity in squamous metaplasia of cervix is associated with the presence of transcriptionally active high-risk HPV even when there are no clear morphologic features of dysplasia. Our results suggest that these lesions are early SILs or SILs that are not yet morphologically evident, most of which arise from SCJ and should be closely followed.

Role of p16/INK4a and Ki-67 as specific biomarkers for cervical intraepithelial neoplasia: An institutional study

BACKGROUND:

P16/INK4a and Ki-67 have emerged as important biomarkers for the detection of high-risk human papilloma virus (HR-HPV) associated dysplastic changes in the cervical biopsy samples. The increasing inter- and intra-observer variability in the diagnosis of dysplastic lesions and immature squamous metaplasia on histopathology has led to the advent of these biomarkers. This study was taken up with an aim to study their role in increasing the diagnostic accuracy in equivocal cases on histopathology.

MATERIALS AND METHODS:

Fifty cervical biopsy specimens were stained with p16/INK4a and Ki-67 consisting of 10 cases each of cervical intraepithelial neoplasia (CIN I/II/III) along with five cases of squamous metaplasia. Histopathological diagnosis was considered as the gold standard. Statistical analysis was done by kappa statistics, and P value was calculated.

RESULTS:

The sensitivity and specificity of p16/INK4a and Ki-67 were 76.2%, 87.5%, 90.5%, and 87.5%, respectively. The overall agreement of both the immunostains with histopathological diagnosis was statistically significant (P < 0.05) and the diagnostic accuracy improved when both the stains were used in conjunction.

CONCLUSION:

Ki-67 and p16/INK4a can be used as complimentary tests in differentiating dysplastic and nondysplastic lesions and help in confirming the histopathological diagnosis. They aid in recognition of dysplasias caused by HR-HPV, which have higher tendency to progress to neoplasia. However, further research is advocated before the widespread use of these markers for screening of dysplasias.

Comparison of cytologic findings between specimens with and without high-risk HPV infection in those with ASC-US judgement

The objective of the study was to realize whether specific signatures for high-risk human papilloma virus (HPV) infection exist in the cytologic specimens with ASC-US judgement or not. The materials are 132 cytologic specimens with the diagnosis of ASC-US, including 56 cases with positive and 76 cases with negative HPV infection. Cytological findings are compared between two groups. Immature squamous metaplastic cells with nuclear atypia, SFT/IMT dyskaryotic cells, atypical parakeratosis, smudgy nuclei and multinucleated cells are the signature of high-risk HPV infection, whereas in the HPV(-) group immature metaplastic cells without atypia, moderately mature metaplastic cells without nuclear atypia and atrophic background are more popular. Instead, there are no differences on SFT/IMT background, microorganism infection and koilocytosis with or without nuclear atypia in both groups. The specific findings to confirm high-risk HPV infection are realized and the present results will contribute to decrease an unnecessary ASC-US judgement.

Prognostic and diagnostic validity of p16/Ki-67, HPV E6/E7 mRNA, and HPV DNA in women with ASCUS: a follow-up study

Background

We evaluated the prognostic and diagnostic ability of p16/Ki-67 immunocytochemistry, HPV E6/E7 mRNA testing and HPV DNA assay in triaging ASCUS to find a way to manage cervical lesions more effectively.

Methods

We conducted a prospective study through follow-up. The detection methods of the three factors: p16/Ki-67 immunocytochemistry conducted by using the CINtec® Plus Kit, E6/E7 mRNA testing by QuantiVirus®HPV E6/E7 mRNA assay and DNA by Hybrid Capture 2 assay.

Results

One hundred three women with ASCUS satisfied requirements and completed the entire follow-up process. All CIN2+ occurred in women who were mRNA positive at baseline, none in mRNA negative. 100% (6/6) patients with CIN2+ were HPV DNA assay positive, 100% (6/6) were HPV E6/E7 mRNA testing positive and 50.0% (3/6) were p16/Ki-67 immunocytochemistry positive. The risk ratio of E6/E7 mRNA test was 57.306 (95% CI 0.077–42,400.545). For endpoint of CIN2+, the sensitivity between HPV DNA assay and HPV E6/E7 mRNA testing is no statistical difference, but statistical difference exists between HPV E6/E7 mRNA testing vs. p16/Ki-67 immunocytochemistry (χ² = 5.718, P = 0.023) and HPV DNA assay vs. p16/Ki-67 immunocytochemistry (χ² = 5.718, P = 0.023). The specificity of E6/E7 mRNA testing, p16/Ki-67 and DNA assay in triaging ASCUS was 44.33, 75.26 and 11.34% respectively and is all statistical difference (χ² = 26.277, P < 0.001(HPV DNA assay vs. HPV E6/E7 mRNA testing), χ² = 19.297, P < 0.001(HPV E6/E7 mRNA testing vs. p16/Ki-67 immunocytochemistry), χ² = 80.707, P < 0.001(HPV DNA assay vs. p16/Ki-67 immunocytochemistry). The expression level of 2097.09 copies/ml was the optimal cut-off value for HPV E6/E7 mRNA testing to diagnose CIN2+, the sensitivity and specificity was 61.1 and 68.2%.

Conclusions

High expression of HPV E6/E7 mRNA could be a good candidate as a diagnostic biomarker to triage ASCUS superseding HPV DNA. p16/Ki-67 immunocytochemistry is suggested to be a good tool to triage ASCUS, but it reduced the sensitivity of diagnosis when improves the diagnostic specificity.

High-level expression of protein tyrosine phosphatase non-receptor 12 is a strong and independent predictor of poor prognosis in prostate cancer

BACKGROUND

Protein tyrosine phosphatase non-receptor 12 (PTPN12) is ubiquitously tyrosine phosphatase with tumor suppressive properties.

METHODS

PTPN12 expression was analyzed by immunohistochemistry on a tissue microarray with 13,660 clinical prostate cancer specimens.

RESULTS

PTPN12 staining was typically absent or weak in normal prostatic epithelium but seen in the majority of cancers, where staining was considered weak in 26.5%, moderate in 39.9%, and strong in 4.7%. High PTPN12 staining was associated with high pT category, high classical and quantitative Gleason grade, lymph node metastasis, positive surgical margin, high Ki67 labeling index and early prostate specific antigen recurrence (p < 0.0001 each). PTPN12 staining was seen in 86.4% of TMPRSS2:ERG fusion positive but in only 58.4% of ERG negative cancers. Subset analyses discovered that all associations with unfavorable phenotype and prognosis were markedly stronger in ERG positive than in ERG negative cancers but still retained in the latter group. Multivariate analyses revealed an independent prognostic impact of high PTPN12 expression in all cancers and in the ERG negative subgroup and to a lesser extent also in ERG positive cancers. Comparison with 12 previously analyzed chromosomal deletions revealed that high PTPN12 expression was significantly associated with 10 of 12 deletions in ERG negative and with 7 of 12 deletions in ERG positive cancers (p < 0.05 each) indicating that PTPN12 overexpression parallels increased genomic instability in prostate cancer.

CONCLUSIONS

These data identify PTPN12 as an independent prognostic marker in prostate cancer. PTPN12 analysis, either alone or in combination with other biomarkers might be of clinical utility in assessing prostate cancer aggressiveness.

Cervical high-grade squamous intraepithelial lesion on conventional cytology: Cytological patterns, pitfalls, and diagnostic clues

BACKGROUND

Conventional cervical cytology, which has a relatively low sensitivity in diagnosing high-grade lesions as compared to liquid-based cytology, is still being practiced in low resource settings. This study aimed at elucidating various cytomorphological patterns, pitfalls, and subtle clues to high-grade squamous intraepithelial lesion (HSIL) diagnosis on conventional cervical cytology through cytologic-histologic correlation.

METHODS

Cervical biopsies reported as CIN2/3 were correlated with their corresponding Pap smears over a 10-year period to determine the frequency of undercalls. For characterization of overcalls, cervical smears reported as HSIL and their corresponding biopsies during the same period were correlated. The discordant cases in both the groups were reviewed for problematic patterns and pitfalls in cytological diagnosis of HSIL.

RESULTS

Of the 142 biopsies with CIN2/3, 29 (20.4%) cases had been undercalled on cytology. Sixteen (16) of these could be reclassified as ASC-H/HSIL on smear review. Smears showing predominant cells of low-grade squamous intraepithelial lesion grade with a few HSIL cells and those with small abnormal cells in an atrophic background formed the main confounders for HSIL underdiagnosis. Thirteen (13) out of 130 (10%) Pap smears called as HSIL, where biopsy diagnosis was less than CIN2, were labeled as overcalls. Atypical metaplasia, hyperchromatic crowded groups, and reparative changes constituted the major diagnostic pitfalls on cytology. A diligent smear review helped to reduce the undercall and overcall rates to 9.1% and 2.3%, respectively.

CONCLUSION

Awareness of morphological challenges in interpretation of HSIL among cytopathologists practicing cervical cytology would assist in reducing the diagnostic errors and ensure better patient management.

Ki-67 and P16 proteins in cervical cancer and precancerous lesions of young women and the diagnostic value for cervical cancer and precancerous lesions

Expression of Ki-67 and P16 proteins in cervical cancer and precancerous lesions of young women and the diagnostic value for cervical cancer and precancerous lesions were investigated. A total of 64 paraffin-embedded specimens of uterus tissue from young female patients who were admitted to Jiading District Central Hospital Affiliated to Shanghai University of Medicine and Health Sciences from January 2015 to December 2017 were selected. According to pathological examination, the specimens were divided into chronic cervicitis group (control group, 10 cases), low-grade squamous intraepithelial lesion (LSIL) group (12 cases), high-grade squamous intraepithelial lesion (HSIL) group (20 cases) and squamous carcinoma of the cervix (SCC) group (22 cases). Expression of Ki-67 and P16 protein was detected by immunohistochemistry and the diagnostic values were analyzed. Positive rates of Ki-67 and P16 expression in HSIL and SCC groups were significantly higher than those in LSIL and control groups (P<0.05), but there was no significant difference between LSIL and control groups (P>0.05). Spearman's analysis showed that the expression levels of Ki-67 and P16 were positively correlated with the degree of cervical lesions (rs=0.725; rs=0.829), and their expression levels were also positively correlated (rs=0.772). Sensitivity and specificity analysis showed that the Ki-67 diagnosis has higher sensitivity (95.2%), but the specificity is poor (86.7%). Diagnosis using P16 has high specificity (94.6%), but the sensitivity is poor (85.4%). When the two were combined for diagnosis, sensitivity (94.8%) and specificity (93.2%) were both at a high level. The combined detection of Ki-67 and P16 protein has a high application prospect as an auxiliary diagnosis of SCC.

Progression of Precancerous Cervical Lesion Predicted by p16 Protein Immunohistochemistry in Rajavithi Hospital

Objective: To assess the association of p16 immunohistochemical (IHC) staining in cervical squamous intraepithelial lesions (SIL) and progression of cervical intraepithelial neoplasia (CIN) 1 to CIN2+ or recurrence of CIN2+. Material and Methods: A retrospective cohort study of women with newly diagnosed SIL from colposcopy-directed biopsy at Rajavithi Hospital, 2013-2017. Pathologic specimens were reviewed and submitted to p16-IHC staining. Adjusted hazard ratios (HR) of disease-free interval (DFI) and 95% confidence intervals (CI) were carried out using the Cox proportional hazard regression model. Results: A total of 187 women was recruited, 91 cases of positive p16-IHC staining and 96 cases of negative staining. With the median follow-up time of 22 months, women with positive p16-IHC had significantly lower 1-year DFI than those with negative p16-IHC (86.8% vs. 96.6%, p = 0.006). Women with CIN 1 had 22.6% of positive p16-IHC, while those with CIN2-3 had 86.7%. From multivariate analysis, the positive p16-IHC and age > 35 years were the significant prognostic factors of progression/recurrent CIN2+ (adjusted HR 5.33, 95%CI 1.77-16.01, p = 0.003; and adjusted HR 5.80, 95%CI 1.34-25.08, p = 0.019, respectively). From subgroup analysis, the positive p16-IHC was the significant prognostic factor in women with initial CIN1 (HR 5.29, 95%CI 1.18-23.76, p = 0.030), but was not associated with prognosis in women with initial CIN 2-3 (HR 2.13, 95%CI 0.28-16.38, p = 0.468). Conclusion: Overexpression of p16 protein has the prognostic significance of SIL. Using p16-IHC may help stratify patients as low-risk and high-risk groups to progression/recurrence CIN2+.

Performance of p16/Ki67 immunostaining, HPV E6/E7 mRNA testing, and HPV DNA assay to detect high-grade cervical dysplasia in women with ASCUS

Background

Atypical squamous cell of undetermined significance (ASCUS) is a common cervical cytological diagnosis. At present, HPV DNA assay is used to triage these patients, but its lower specificity brings a series of problems. The purpose of this study was to evaluated the value of p16/Ki67 immunostaining, HPV E6/E7 mRNA testing in triaging women with ASCUS by comparing HPV DNA assay.

Methods

Liquid based cytology specimens were collected from 300 patients. P16/Ki67 immunocytochemistry using the CINtec® Plus Kit and HPV E6/E7 mRNA testing by QuantiVirus®HPV E6/E7 mRNA assay used the same cytology sample. Detection rates of each test were evaluated against histopathology.

Results

All assays yielded a high sensitivity for the detection of CIN3+ (100% (86.7–100) for HPV DNA assay, 88.0% (70.0–95.8) for HPV E6/E7 mRNA testing and 100% (86.7–100) for p16/Ki67 immunocytochemistry) and CIN2+ (98.2% (90.2–99.7) for HPV DNA assay, 87.0% (75.6–93.6) for HPV E6/E7 mRNA testing, 98.2% (90.2–99.7) for p16/Ki67 immunocytochemistry). The specificity to detect high grade dysplasia was highest for p16/Ki67 immunocytochemistry (74.2% (68.7–79.0) in CIN3+ and 82.5% (77.3–86.8) in CIN2+), followed by HPV E6/E7 mRNA testing (39.6% (34.0–45.5) in CIN3+ and 42.7% (36.7–48.9) in CIN2+) and HPV DNA assay (16.0% (12.1–20.8) in CIN3+ and 17.5% (13.2–22.7) in CIN2+).

Conclusions

p16/Ki67 immunostaining and HPV E6/E7 mRNA testing, especially the former, may be promising tools in triage of ASCUS.

Vulvar and Anal Intraepithelial Neoplasia: Terminology, Diagnosis, and Ancillary Studies

Currently, it is recognized that there is an HPV-related and an HPV-independent pathway to developing squamous cell carcinomas (SCC) in the anus and vulva. The majority of precursor lesions and SCC in the anus and vulva are high-risk HPV-associated, with HPV16 the most common type. Given the morphologic overlap and biological equivalence of HPV-related preinvasive squamous lesions of the lower anogenital tract, a unified, 2-tiered histopathologic nomenclature is now recommended. In contrast, mutations in the TP53 gene have been associated with HPV-independent vulvar and anal SCC. A precursor lesion-differentiated or simplex vulvar intraepithelial neoplasia (dVIN)-has been identified for HPV-independent vulvar SCC but a similar lesion in the anus has not been described. Extramammary Paget disease is a nonsquamous intraepithelial lesion of the vulva and anus that may be a primary epidermotropic apocrine neoplasm or may represent secondary involvement by a synchronous/metachronous adenocarcinoma. This entity may be mimicked by squamous lesions and melanocytic lesions. Herein, we discuss the morphologic and immunohistochemical features of anal and vulvar intraepithelial neoplasia in the context of updated terminology and current understanding of disease biology.

Improved survival in p16-positive vaginal cancers across all tumor stages but no correlation with MIB-1

OBJECTIVES

Survival as it relates to p16 overexpression and MIB-1 (Ki-67) proliferation in primary squamous cell vaginal carcinoma was studied.

METHODS

Retrospective chart review from 1997 to 2006 revealed 43 patients who were treated for primary vaginal cancer at Emory University hospitals. Tissue was evaluated by immunohistochemical staining for the presence of p16 and MIB-1 markers, and survival data were examined.

RESULTS

Patients who had primary squamous cell vaginal cancers (n = 31) with a positive diffuse staining of p16 had significantly (P = .003) improved survival (~49.5 months) compared with p16-negative patients (~25.3 months). Stage-specific analysis with 30 additional reported cases showed a significant survival benefit for p16-positive vaginal cancers compared with p16-negative cancers for stages I and II (P = .017; hazard ratio [HR] 0.400; 95% confidence interval [CI], 0.189-0.850) and stages III and IV (P = .001; HR, 0.176; 95% CI, 0.066-0.479). No difference was observed in survival for MIB-1-positive tumors (P = .984; HR, 1.008; 95% CI, 0.483-2.104).

CONCLUSIONS

The p16 marker has a significant prognostic impact in primary squamous cell vaginal cancers across all tumor stages.

Biomarkers of HIV-associated Cancer

Cancer biomarkers have provided great opportunities for improving the management of cancer patients by enhancing the efficiency of early detection, diagnosis, and efficacy of treatment. Every cell type has a unique molecular signature, referred to as biomarkers, which are identifiable characteristics such as levels or activities of a myriad of genes, proteins, or other molecular features. Biomarkers can facilitate the molecular definition of cancer, provide information about the course of cancer, and predict response to chemotherapy. They offer the hope of early detection as well as tracking disease progression and recurrence. Current progress in the characterization of molecular genetics of HIV-associated cancers may form the basis for improved patient stratification and future targeted or individualized therapies. Biomarker use for cancer staging and personalization of therapy at the time of diagnosis could improve patient care. This review focuses on the relevance of biomarkers in the most common HIV-associated malignancies, namely, Kaposi sarcoma, non-Hodgkin’s lymphoma, and invasive cervical cancer.

Factors influencing decisions about surgical treatment of cervical precancerous lesions

Cervical precancerous lesions represented by cervical intraepithelial neoplasia (CIN) and cervical glandular intraepithelial neoplasia may progress to invasive cancer. The principle treatment of CIN is eradication of the transformation zone. However, all eradication methods are associated with some adverse events, particularly with perinatal consequences. It is therefore necessary to identify which women have CIN that has a low risk of transformation into invasive cancer. The presence of modifying factors can help to stratify CIN lesions according to their malignant potential. The evaluation of HPV genotype in particular holds great promise for defining patients at greater risk. Tailoring treatment to the individual patient is going to become a major consideration in the management of cervical precancerous lesions.

Variability of Pathologists' Utilization of p16 and Ki-67 Immunostaining in the Diagnosis of Cervical Biopsies in Routine Pathology Practice and Its Impact on the Frequencies of Cervical Intraepithelial Neoplasia Diagnoses and Cytohistologic Correlations

Context.—The use of p16 in cervical biopsies improves the accuracy of cervical intraepithelial neoplasia (CIN) diagnosis and grading and decreases its interpathologist variability.

Objective.—To determine the impact of the frequency of use of p16 immunostains in cervical biopsies on pathologists' diagnoses of CIN grade 1 and grade 2 or above (CIN1 and CIN2+) and on cytohistologic correlations.

Design.—We identified all cervical biopsy specimens with cytologic correlations subjected or not to p16 staining from January 1, 2005, to September 30, 2010; calculated each pathologist's percentage of p16 use; and correlated it with their major cytohistologic discrepancy rates, CIN2+ diagnoses, and CIN1/CIN2+ ratios.

Results.—During the study period, each of the 23 pathologists interpreted 59 to 1811 (mean, 518) of 11 850 cervical biopsy specimens, used p16 for 0% to 21.31% (mean, 10.14%) of these, had CIN2+ detection rates of 9.5% to 24.1% (mean, 18.9%), and CIN1/CIN2+ ratios of 0.7 to 4.5 (mean, 1.5). Compared to the 12 “low users” of p16, who used p16 fewer times than the institution's mean for p16 use, the 11 “high users” of p16 diagnosed more biopsies (8391 versus 3459), had a lower rate of major cytohistologic discrepancies (12.62% versus 14.92%, P &lt; .001), a higher rate of CIN2+ diagnoses (19.9% versus 16.4%, P &lt; .001), a lower range of CIN2+ rates (15.0%–23.1% versus 9.5%–24.1%), and lower CIN1/CIN2+ ratios (1.2 versus 2.3).

Conclusions.—We found a high intrainstitutional variability of p16 use in cervical biopsies, CIN2+ rates, and CIN1/CIN2+ ratios. Use of p16 for greater than 10% of cervical biopsies was associated with improved cytohistologic correlation rates and with lower variability in the frequencies of histologic diagnoses.

E4 antibodies facilitate detection and type-assignment of active HPV infection in cervical disease

High-risk human papillomavirus (HPV) infections are the cause of nearly all cases of cervical cancer. Although the detection of HPV DNA has proved useful in cervical diagnosis, it does not necessarily predict disease presence or severity, and cannot conclusively identify the causative type when multiple HPVs are present. Such limitations may be addressed using complementary approaches such as cytology, laser capture microscopy, and/or the use of infection biomarkers. One such infection biomarker is the HPV E4 protein, which is expressed at high level in cells that are supporting (or have supported) viral genome amplification. Its distribution in lesions has suggested a role in disease staging. Here we have examined whether type-specific E4 antibodies may also allow the identification and/or confirmation of causal HPV-type. To do this, type-specific polyclonal and monoclonal antibodies against three E4 proteins (HPV-16, -18, and -58) were generated and validated by ELISA and western blotting, and by immunohistochemistry (IHC) staining of epithelial rafts containing these individual HPV types. Type-specific detection of HPV and its associated disease was subsequently examined using formalin-fixed paraffin-embedded cervical intra-epithelial neoplasias (CIN, (n = 247)) and normal controls (n = 28). All koilocytotic CIN1 lesions showed type-specific E4 expression of their respective HPV types. Differences were noted amongst E4 expression patterns in CIN3. HPV-18 E4 was not detected in any of the 6 HPV-18 DNA-positive CIN3 lesions examined, whereas in HPV-16 and -58 CIN3, 28/37 (76%) and 5/9 (55.6%) expressed E4 respectively, usually in regions of epithelial differentiation. Our results demonstrate that type-specific E4 antibodies can be used to help establish causality, as may be required when multiple HPV types are detected. The unique characteristics of the E4 biomarker suggest a role in diagnosis and patient management particularly when used in combination.

Role of protein biomarkers in the detection of high-grade disease in cervical cancer screening programs

Since the Pap test was introduced in the 1940s, there has been an approximately 70% reduction in the incidence of squamous cell cervical cancers in many developed countries by the application of organized and opportunistic screening programs. The efficacy of the Pap test, however, is hampered by high interobserver variability and high false-negative and false-positive rates. The use of biomarkers has demonstrated the ability to overcome these issues, leading to improved positive predictive value of cervical screening results. In addition, the introduction of HPV primary screening programs will necessitate the use of a follow-up test with high specificity to triage the high number of HPV-positive tests. This paper will focus on protein biomarkers currently available for use in cervical cancer screening, which appear to improve the detection of women at greatest risk for developing cervical cancer, including Ki-67, p16^INK4a, BD ProEx C, and Cytoactiv HPV L1.

One virus, one lesion--individual components of CIN lesions contain a specific HPV type

In 20-40% of cervical intra-epithelial neoplasia (CIN) and in 4-8% of cervical carcinoma tissue specimens, multiple HPV genotypes have been detected. Whole tissue section (WTS) PCR does not determine how the individual types relate causally to complex and multiple CIN. Our objective was to determine whether laser capture micro-dissection (LCM) with HPV PCR genotyping (LCM-PCR) could accurately recover type-specific HPV DNA from epithelial cells in individual areas of CIN and normal epithelium, and whether one or more viruses are present in one lesion. For that, histologically selected samples of CIN and normal epithelium were isolated by LCM and analysed by the SPF(10) PCR/LiPA(25) (version 1) HPV genotyping system for 25 HPV genotypes. HPV genotypes detected in 756 areas of CIN (grade 1, 2 or 3) by LCM-PCR were compared with results obtained by WTS-PCR in 60 cases (74 biopsies). We showed that when a single HPV type is detected by WTS-PCR, that type was almost always (94%; 29/31) recovered by LCM-PCR from CIN. When multiple HPV types were present by WTS-PCR, their distribution within histological sections could be mapped by LCM-PCR. Association of a single HPV type with a discrete area of CIN was found for 93% (372/399) of LCM fragments analysed by PCR. We found colliding CIN lesions associated with separate HPV types and only 62% (61/99) of HPV types detected by WTS-PCR were found in CIN by LCM-PCR. Therefore, the LCM-PCR technique was found very accurate for high-resolution HPV genotyping and for assigning an individual HPV type to an area of CIN. At LCM level, in cervical biopsy sections with multiple HPV infections, the relation between HPV types and CIN lesions is often complex. Almost every HPV type found in CIN by LCM-PCR is associated with a biological separate independent CIN lesion-one virus, one lesion.

Neoplastic Lesions of the Cervix

This review presents a discussion of the gross and microscopic features, diagnosis, differential diagnosis, and prognosis of neoplastic lesions of the cervix. Biomarkers are discussed for each entity presented - cervical intraepithelial neoplasia, squamous carcinoma, glandular neoplasms, adenocarcinoma in situ, adenosquamous carcinoma, and others.

MOLECULAR MARKERS OF EARLY CERVICAL NEOPLASIA

Pure morphological distinction of high-grade squamous intraepithelial lesions (HSILs) from their mimics can be challenging. Diagnosis can be difficult with nonconventional HSILs associated with a metaplastic phenotype, squamous intraepithelial lesions (SILs) that defy precise classification such as "eosinophilic dysplasias", and those that overlap with columnar neoplasms, including stratified variants of adenocarcinoma in situ ("SMILE"). Gene expression and protein profiling have identified biomarkers with the potential to decrease diagnostic variability and increase specificity of histological and cytological analysis. Among the ones clinically useful for HSIL detection are p16(INK4A) and MIB-1 which complement each other, differentiating SIL from normal/atrophic (MIB-1 low) or reactive/immature metaplastic (p16(INK4A) scattered) epithelium. Additional markers, including ProEx(TM) C, have been proposed but their added value is yet to be established. In the final analysis, biomarkers are most helpful for distinguishing benign immature or atrophic proliferations from HSIL. The distinction of LSIL from HSIL must be made on the hematoxylin and eosin-stained section and should be made with care, given the potential consequences of a diagnosis of CIN2 or CIN3.

[Human papillomaviruses in the pathogenesis of intraepithelial neoplasia (AIN) and carcinoma of the anus]

HPV infections have been implicated in the pathogenesis of anal cancers. The mode of infection and subsequent transformation resembles very much the pathogenesis of cervical and other HPV-associated cancers. The molecular dissection of individual steps required to achieve cellular transformation within an HPV-infected cell led to the identification of novel biomarkers that make it possible to identify HPV-transformed cells with substantially higher precision in comparison to conventional methods. Since effective antiretroviral therapy allows for possible long-term survival of HIV-infected individuals who are at very high risk to develop HPV-associated cancers in the anogenital tract, these new developments have become increasingly relevant for practicing dermatologists and proctologists. We here briefly review the basic concepts and some clinical applications of this recent research.

Effect of human papillomavirus on cell cycle-related proteins p16, Ki-67, Cyclin D1, p53, and ProEx C in precursor lesions of cervical carcinoma: a tissue microarray study

In-depth study of cell cycle proteins and human papillomavirus (HPV) genotyping can provide useful information about the malignant potential of precursor lesions of cervical carcinoma (CC). Immunostaining of cell cycle-related proteins (p16, cyclin D1, Ki-67, p53, and ProEx C) was evaluated using tissue microarrays, and HPV genotypes were identified in 144 cervical tissue specimens encompassing normal or benign epithelial lesions, low- and high-grade squamous intraepithelial lesions (LSIL and HSIL, respectively), and CC. In addition, 14 cases with atypical immature metaplasia (AIM) were included to compare their immunohistochemical features with those of well-established precursor lesions. Expression of p16, Ki-67, and ProEx C was most associated with the severity of dysplasia. Positive expression of p16, Ki-67, and ProEx C and negative expression of p53 seem to be related to HPV-16 infection. AIM cases show an immunohistochemical pattern more similar to LSIL than to HSIL. Immunohistochemical assessment of cell cycle proteins may help to distinguish normal and benign conditions of the cervix from precursor lesions of CC.

Current concepts in cervical pathology

CONTEXT

The correct diagnosis and reporting of cervical in situ and invasive carcinoma are essential for the appropriate clinical management of patients with human papillomavirus-associated disease.

OBJECTIVES

To review common mistakes made in the diagnosis of cervical dysplasia and invasive carcinoma, describe variants and benign mimics of high-grade squamous intraepithelial lesion and adenocarcinoma in situ, and discuss available ancillary studies that can be useful in making the distinctions as well as to review important factors related to prognosis that should be included in the pathology report.

DATA SOURCES

Review of current literature.

CONCLUSIONS

There are many mimics and variants of cervical squamous and glandular lesions that can be resolved with ancillary studies and careful histologic examination. Prognostically important features, such as tumor size, presence of vascular invasion, and margin status, should always be included in the pathology report.

p16(INK4a) immunostaining in cytological and histological specimens from the uterine cervix: a systematic review and meta-analysis

BACKGROUND

P16(INK4a) is a biomarker for transforming HPV infections that could act as an adjunct to current cytological and histological assessment of cervical smears and biopsies, allowing the identification of those women with ambiguous results that require referral to colposcopy and potentially treatment.

MATERIAL AND METHODS

We conducted a systematic review of all studies that evaluated the use of p16(INK4a) in cytological or histological specimens from the uterine cervix. We also estimated the mean proportion of samples that were positive for p16(INK4a) in cytology and histology, stratified by the grade of the lesion.

RESULTS

Sixty-one studies were included. The proportion of cervical smears overexpressing p16(INK4a) increased with the severity of cytological abnormality. Among normal smears, only 12% (95% CI: 7-17%) were positive for the biomarker compared to 45% of ASCUS and LSIL (95% CI: 35-54% and 37-57%, respectively) and 89% of HSIL smears (95% CI: 84-95%). Similarly, in histology only 2% of normal biopsies (95% CI: 0.4-30%) and 38% of CIN1 (95% CI: 23-53%) showed diffuse staining for p16(INK4a) compared to 68% of CIN2 (95% CI: 44-92%) and 82% of CIN3 (95% CI: 72-92%).

CONCLUSION

Although there is good evidence that p16(INK4a) immunostaining correlates with the severity of cytological/histological abnormalities, the reproducibility is limited due to insufficiently standardized interpretation of the immunostaining. Therefore, a consensus needs to be reached regarding the evaluation of p16(INK4a) staining and the biomarker needs to be assessed in various clinical settings addressing specific clinical questions.

Squamous intraepithelial lesions arising in benign endocervical polyps: a report of 9 cases with correlation to the Pap smears, HPV analysis, and immunoprofile

Endocervical polyps are common benign lesions that typically arise in the endocervical canal of women from 40 to 60 years old. The reported incidence of squamous intraepithelial lesion (SIL) occurring in an endocervical polyp is typically less than 1/1,000 (0.1%). We report on 9 cases of SIL arising in otherwise classic benign endocervical polyps; these lesions were from a pool of about 1500 endocervical polyps for an incidence of approximately 0.5%. Five cases were low-grade SIL; of the 4 cases of high-grade SIL, 1 was associated with an invasive squamous cell carcinoma. In 8/9 cases, there was no evidence of SIL on colposcopic examination or biopsy of the remainder of the cervix. There were 12 Pap smears (either concurrent or from 6 mo to 2 yr before the biopsy-proven SIL) taken from the 9 women and most (10/12%-83%) were diagnosed as normal (7), atypical squamous cells of undetermined significance (ASCUS), favor reactive changes (1), or ASCUS (2) whereas the other 2 (17%) smears were diagnosed as low-grade SIL. Human papillomavirus DNA was evident in 7/8 (88%) of the polyps with SIL as determined by in situ hybridization. We conclude that cervical SILs can occur de novo in endocervical polyps, their incidence may be increasing, and, due to their presence in the endocervical canal, where they are much less accessible to sampling with a cytobrush/spatula, may not be evident in the Pap smear.

Detection of HPV-induced cervical (pre) neoplastic lesions: a tissue microarray (TMA) study

The aim of this study was to evaluate the usefulness of a panel of biomarkers in the characterization of human papillomavirus (HPV)-induced cervical lesions. Management of these lesions depends on their histologic confirmation. Misinterpretation especially for benign mimics results in a significant diagnostic disagreement. For these reasons, a continuous effort is still needed to discover surrogate markers, which could support the final diagnosis. Archival biopsies of normal ectocervical and endocervical tissues, squamous metaplasia, cervical intraepithelial neoplasia (CIN), squamous cell carcinoma, adenocarcinoma in situ, and adenocarcinoma were retrieved to perform a tissue microarray (TMA). A panel of markers was tested on the TMA obtained slides by in situ hybridization (HPV DNA) and immunohistochemistry (p16, involucrin, Ki-67, and HPV L1 proteins). The sensitivity to detect high-risk HPV DNA increased with lesion's severity. In situ hybridization signals suggesting integrated viral physical status predominated in CIN II/III, squamous cell carcinoma, and glandular (pre) neoplastic lesions. The p16 and Ki-67 protein expression increased from CIN I to CIN III and to infiltrative lesions. Involucrin positivity was better appreciated in well-differentiated diagnostic entities (ectocervix, mature metaplasia, and CIN I). HPV L1 antibody detected the viral capsid protein in a low proportion of CIN I and II. In conclusion, using a panel of cervical biomarkers improves the final reporting of various HPV-induced epithelial lesions. Carefully constructed TMA with single spots of 1-mm diameter are powerful tools, which have a high reliability in representing full tissue sections.

P16/Ki-67 Immunostaining is Useful in Stratification of Atypical Metaplastic Epithelium of the Cervix

Cervical metaplastic squamous epithelium exhibiting atypia insufficient for a diagnosis of cervical intraepithelial neoplasia (CIN) is usually reported as "atypical squamous metaplasia" (ASM). Stratification impacts treatment since the differential is often between reactive and high grade CIN (CIN II, III). Diagnosis with H&E is associated with low intra/interobserver concurrence. P16/Ki-67 immunostains are helpful to assess cervical biopsies for HPV-associated lesions but staining in metaplastic squamous epithelium has received little attention. This study aims to establish staining characteristics of metaplastic squamous epithelium and determine if p16/Ki-67 is useful in ASM stratification. 80 cervical biopsies containing morphologically normal and dysplastic squamous metaplasia were retrieved to determine the staining characteristics of metaplastic epithelium utilizing p16/Ki-67 immunostains. These included 21 benign squamous metaplasia (BSM) from benign cervices, 15 BSM present adjacent to HPV/CIN lesions, and 44 CIN involving squamous metaplasia. Serial sections with controls were stained for p16 and Ki-67 and in-situ hybridization (ISH) for low-risk (LR) and high-risk (HR) HPV was performed. P16 was recorded as negative, spotty, or band-like. Ki-67 was recorded as positive when present in >50% of lesional nuclei. Results were correlated with H&E diagnosis. 95% of the BSMs, whether from normal cervices or adjacent to HPV/CIN were p16/Ki-67 negative. 81% HG CINs involving squamous metaplasia were p16 band/Ki-67 positive. Low grade CIN (CIN I) involving metaplastic epithelium showed a broad distribution of p16/Ki-67 staining patterns. Based on these criteria, 20 ASM were evaluated. 10% of the ASM cases were p16 band/Ki-67 positive indicating HG CIN. 60% of the ASMs were p16/Ki-67 negative indicating reactive change (all with the exception of one case being HPV negative). The remaining 30% of the ASM cases showed variable positivity for p16 and Ki-67 and could not be stratified into the two categories. Thus p16/Ki-67 staining is helpful in stratification of ASM as reactive or CIN.

Prevalence of mucosal and cutaneous human papillomaviruses in different histologic subtypes of vulvar carcinoma

Two independent pathways of vulvar carcinogenesis have currently been identified, one related to infection with mucosal human papillomaviruses (HPVs) and a second related to chronic inflammatory or autoimmune processes. The goal of the study was to examine a possible role of cutaneous HPVs from the beta genus in vulvar carcinogenesis and to evaluate the distribution of intratypic variants of HPV 16 in HPV 16-positive vulvar cancer. Consecutive cases of vulvar carcinoma were retrieved from the files and included the following histologic subtypes: keratinizing (n=21), basaloid (n=7), warty (n=1), mixed basaloid-warty (n=4), verrucous (n=4), keratoacanthoma (n=1), basal cell carcinoma (n=1). All tumors were microdissected and tested for 25 beta HPV types and 25 mucosal HPV types. Cases identified as positive for HPV 16 were further tested for intratypic variants. All cases were immunostained for p16INK4a. Beta HPVs were not detected in any of the tumor cases. Mucosal HPVs were detected in all but one basaloid/warty carcinomas; of these, nine cases (82%) were positive for HPV 16, including five European subtypes, one African subtype, one North American subtype and two indeterminate subtypes. Two of four verrucous carcinomas were positive for HPV 6. Mucosal HPVs were not detected in keratinizing carcinomas, keratoacanthoma and basal cell carcinoma. All cases of basaloid/warty carcinomas, but none of the remaining tumors, overexpressed p16INK4a protein. Our data do not support a role of beta HPVs in the pathogenesis of vulvar carcinoma. The study reaffirms the role of mucosal HPVs, in particular that of HPV 16, in the pathogenesis of basaloid and warty tumor subtypes. The HPV 16 intratypic variation showed correlation with patients' ethnic background. P16INK4a immunostaining seems to be a sensitive and specific marker of vulvar carcinomas positive for oncogenic mucosal HPVs.