Interobserver and intraobserver bias exists in the interpretation of anal dysplasia

Anal and Perianal Preneoplastic Lesions

Anal cancer, mainly squamous cell carcinoma, is rare but increasing in prevalence, as is its precursor lesion, anal squamous dysplasia. They are both strongly associated with human papillomavirus infection. The 2-tiered Lower Anogenital Squamous Terminology classification, low-grade SIL and high-grade SIL, is preferred to the 3-tiered anal intraepithelial neoplasia classification because of better interobserver agreement and clearer management implications. Immunohistochemistry with p16 is helpful to corroborate the diagnosis of squamous dysplasia. Similarly, immunohistochemistry is helpful to differentiate primary Paget disease from secondary Paget disease, which is usually due to anal squamous mucosal/epidermal involvement by primary rectal adenocarcinoma.

Anal intraepithelial neoplasia: a review of terminology, differential diagnoses, and patient management

Despite the knowledge of etiological association with high-risk human papilloma viruses and high-risk patient cohorts, the incidence of anal squamous cell carcinoma has continued to rise. The known precursor lesion (in particular, high-grade squamous intraepithelial lesion) makes it amenable to screening and surveillance strategies. However, the diagnosis of anal intraepithelial neoplasia suffers from interpretation challenges leading to high interobserver variability, along with numerous differential diagnoses and lingering terminology issues. Proper treatment of anal lesions requires accurate diagnosis, and while a variety of modalities are available for treatment, the rate of recurrence remains high and each modality has its own set of side effects and complications. The aim of this review article is to outline the diagnostic considerations and provide practical tips for diagnosing anal squamous intraepithelial lesions.

Neural network-based method for diagnosis and severity assessment of Graves' orbitopathy using orbital computed tomography

Computed tomography (CT) has been widely used to diagnose Graves' orbitopathy, and the utility is gradually increasing. To develop a neural network (NN)-based method for diagnosis and severity assessment of Graves' orbitopathy (GO) using orbital CT, a specific type of NN optimized for diagnosing GO was developed and trained using 288 orbital CT scans obtained from patients with mild and moderate-to-severe GO and normal controls. The developed NN was compared with three conventional NNs [GoogleNet Inception v1 (GoogLeNet), 50-layer Deep Residual Learning (ResNet-50), and 16-layer Very Deep Convolutional Network from Visual Geometry group (VGG-16)]. The diagnostic performance was also compared with that of three oculoplastic specialists. The developed NN had an area under receiver operating curve (AUC) of 0.979 for diagnosing patients with moderate-to-severe GO. Receiver operating curve (ROC) analysis yielded AUCs of 0.827 for GoogLeNet, 0.611 for ResNet-50, 0.540 for VGG-16, and 0.975 for the oculoplastic specialists for diagnosing moderate-to-severe GO. For the diagnosis of mild GO, the developed NN yielded an AUC of 0.895, which is better than the performances of the other NNs and oculoplastic specialists. This study may contribute to NN-based interpretation of orbital CTs for diagnosing various orbital diseases.

Interobserver Agreement in the Diagnosis of Anal Dysplasia: Comparison Between Gastrointestinal and Gynaecologic Pathologists and Utility of Consensus Conferences

INTRODUCTION

Management of anal dysplasia relies on the accurate diagnosis of anal biopsy specimens. As institutions move toward subspecialty signout (SSSO), decisions must be made regarding whether to assign anal biopsies to the gastrointestinal (GI) or gynaecologic (GYN) pathology service.

MATERIALS AND METHODS

We identified 200 archival tissue biopsies of anal mucosa and circulated them among three GI pathologists and three GYN pathologists. Each pathologist separately scored each biopsy as normal, atypical, LSIL, or HSIL. Every case that was called HSIL by at least one pathologist was stained with p16 immunostain and a "gold standard" interpretation of whether a case represented HSIL was made.

RESULTS

The GI pathologists agreed on 97 (49%) cases prior to consensus; the GYN pathologists agreed on 33 (17%). The sensitivities of the 3 GI pathologists in detecting HSIL against the "gold standard" were 47%, 100%, and 21%, and for the GYN pathologists the sensitivities were 74%, 89%, and 84%; the sensitivities of both the GI and GYN consensus diagnoses were 74% each. The specificities of the 3 GI pathologists in detecting HSIL were 99%, 90%, and 100%, and for the GYN pathologists the specificities were 99%, 92%, and 91%; the specificities of both the GI and GYN consensus diagnoses were 100%.

CONCLUSIONS

A mild to moderate degree of interobserver variability exists in the diagnosis of anal dysplasia among pathologists. Our study does indicate the utility of some form of consensus conference, as overall agreement among GI pathologists and among GYN pathologists improved following in-person consensus.

Diagnosing Anal Squamous Intraepithelial Lesions With and Without p16: An Interobserver Variability Study

OBJECTIVE

Morphologic diagnosis and grading of anal squamous intraepithelial lesions (ASILs) are challenging. In this study, we investigated interobserver variability and p16 utility in accurately grading anal SIL.

MATERIALS AND METHODS

Six pathologists evaluated the degree of SIL on hematoxylin and eosin slides from 146 anal biopsies, followed by the review of both p16 and hematoxylin and eosin slides in cases where p16 was previously performed. κ was calculated in the following 4 ways: (A) 4-tiered diagnosis (negative for SIL [NSIL], anal intraepithelial neoplasia [AIN 1, AIN 2, AIN 3]); (B) 3-tiered diagnosis (NSIL and AIN 1 [pooled], AIN 2, AIN 3); (A) 3-tiered diagnosis (NSIL, low-grade SIL, high-grade SIL [HSIL]); and (D) 2-tiered diagnosis (no HSIL, HSIL).

RESULTS

There is only moderate agreement with a 4-tiered diagnosis with or without p16 (κ = 0.48-0.57). There is substantial agreement when AIN 2 and AIN 3 are pooled as HSIL in cases with or without p16 review (κ = 0.71-0.78). There is almost perfect agreement with a 2-tiered diagnosis of negative for HSIL and HSIL both in cases where p16 was used and where p16 was not required, with the best agreement for a 2-tiered diagnosis with concurrent p16 review.

CONCLUSIONS

This study highlights the importance of a judicious use of p16 for diagnosis. When there is no need for p16 by the Lower Anogenital Squamous Terminology guidelines, interobserver agreement was substantial to almost perfect with a 2-tiered diagnosis. However, when its use is indicated but it is not performed or reviewed, the agreement is much lower even with a 2-tiered diagnosis. Rational use of p16 will ensure diagnostic accuracy and the best possible patient care.

Histopathological Image QTL Discovery of Immune Infiltration Variants

Genotype-to-phenotype association studies typically use macroscopic physiological measurements or molecular readouts as quantitative traits. There are comparatively few suitable quantitative traits available between cell and tissue length scales, a limitation that hinders our ability to identify variants affecting phenotype at many clinically informative levels. Here we show that quantitative image features, automatically extracted from histopathological imaging data, can be used for image quantitative trait loci (iQTLs) mapping and variant discovery. Using thyroid pathology images, clinical metadata, and genomics data from the Genotype-Tissue Expression (GTEx) project, we establish and validate a quantitative imaging biomarker for immune cell infiltration. A total of 100,215 variants were selected for iQTL profiling and tested for genotype-phenotype associations with our quantitative imaging biomarker. Significant associations were found in HDAC9 and TXNDC5. We validated the TXNDC5 association using GTEx cis-expression QTL data and an independent hypothyroidism dataset from the Electronic Medical Records and Genomics network.

Proposed Terminology for Anal Squamous Lesions: Its Application and Interobserver Agreement Among Pathologists in Academic and Community Hospitals

OBJECTIVES

To analyze interobserver reproducibility and compare practice patterns between academic and community settings of Lower Anogenital Squamous Terminology (LAST).

METHODS

In total, 132 anal biopsy slides were revised as well as p16 immunostains.

RESULTS

LAST was used in 49% of cases (academic center, 68%; satellite hospitals [community practice setting], 32%). After pathology review and consensus interpretation, 23 (17%) case diagnoses were reclassified: eight (34.8%) cases (benign or low-grade squamous intraepithelial lesion [LSIL]) were upgraded to high-grade squamous intraepithelial lesion (HSIL) (p16 confirmed ordered during review); four (17.4%) cases originally classified as HSIL were downgraded to LSIL (p16 originally ordered in one case). There was no significant difference in discrepancies between original and consensus diagnosis in the community vs academic setting or by subspecialty (gynecological vs gastrointestinal). Overall interobserver agreement among reviewers was substantial (κ = 0.63) and improved with the use of p16 immunostain in challenging cases (κ = 0.71; P < .001).

CONCLUSIONS

This new terminology is not yet uniformly used by pathologists in anal/perianal biopsy specimens; this two-tier system has a good interobserver agreement and is further improved with p16 use in appropriate cases.

High reproducibility of histological diagnosis of human papillomavirus-related intraepithelial lesions of the anal canal

In a natural history study of anal human papillomavirus (HPV) infection and HPV-related lesions, we examined the reproducibility of histological high-grade squamous intraepithelial lesion (HSIL). Three expert anogenital pathologists share the reporting of histological specimens from the Study of the Prevention of Anal Cancer (SPANC), utilising Lower Anogenital Squamous Terminology (LAST) criteria. In total, 194 previously reported biopsies were randomly chosen within diagnostic strata [50 HSIL-anal intraepithelial neoplasia (AIN) 3; 45 HSIL-AIN 2; 49 'flat' low-grade squamous intraepithelial lesion (LSIL); 50 'exophytic' LSIL; and 50 negative for squamous intraepithelial lesion] and reviewed by each of these three pathologists. Consensus was defined as agreement between at least two review diagnoses, using a binary classification of HSIL and non-HSIL, or if consensus was not obtained in this way, it was achieved through a multiheader microscope session by the three pathologists. We found very high agreement between original and consensus diagnoses (Kappa = 0.886) and between each pathologist's review and consensus (Kappas = 0.926, 0.917 and 0.905). Intra-observer agreement for the three pathologists was 0.705, 1.000 and 0.854. This high level of diagnostic reproducibility indicates that the findings of SPANC should be robust and provide reliable information about HPV-related anal canal disease.

An update on anal neoplasia

Although anal cancer remains a relatively uncommon tumour its frequency is rising, especially in high-risk groups. It is now well recognized that anal squamous cell carcinoma, the largely predominant tumour type, shares many similarities with cancer of the uterine cervix, with a major role for oncogenic human papilloma viruses in both tumours. Anal squamous precancerous lesions have now to be classified with the same criteria and terminology as their cervical counterparts, by using the Lower Anogenital Squamous Terminology (LAST) proposal. Only p16 protein is a useful marker in this setting at the present time. As most cases of anal cancer are treated by non-surgical procedures, pathology has a limited role in the staging of the disease, except for early lesions treated by local excision, and when the sentinel lymph node procedure is undertaken that is still under evaluation. A variety of other tumour types can occur more rarely, with difficult diagnostic issues, solved in most cases by immunohistochemistry.

Utility of Human Papillomavirus Capsid Protein L1 and p16 in the Assessment and Accurate Classification of Anal Squamous Intraepithelial Lesions

OBJECTIVES

Morphologic evaluation of anal dysplasia remains problematic, especially in cases with limited biopsy samples or obscuring inflammation. Studies in cervical neoplasia have shown that human papillomavirus (HPV) L1 capsid production is highest in low-grade squamous intraepithelial lesions (LSILs) and progressively decreases in high-grade squamous intraepithelial lesions (HSILs). The combined utility of HPV L1 and p16 expression in assessing anal squamous intraepithelial lesions (SILs) has never been analyzed and forms the basis of this study.

METHODS

In total, 145 anal lesions were reviewed and immunohistochemically stained for HPV L1 and p16. p16 expression was recorded as negative, patchy/focal, or diffuse. For analytical purposes, condylomas were evaluated separately from rest of the LSILs.

RESULTS

There were 34 (23%) condylomas, 64 (44%) LSILs, and 47 (32%) HSILs. HPV L1 was significantly associated with condylomas (68%) and LSILs (52%) compared with HSILs (9%; P < .0001). Diffuse p16 staining was present only in HSILs (P < .0001), whereas a patchy/focal p16 staining pattern was observed in both LSILs and condylomas.

CONCLUSIONS

HPV L1 and diffuse p16 expression is mutually exclusive in most anal SILs and helps separate LSIL and HSIL cases. Application of both HPV L1 and p16 can not only facilitate accurate grading but also contribute to risk assessment in anal neoplasia.

High-resolution anoscopy or expectant management for anal intraepithelial neoplasia for the prevention of anal cancer: is there really a difference?

BACKGROUND

High-resolution anoscopy has been shown to improve identification of anal intraepithelial neoplasia but a reduction in progression to anal squamous-cell cancer has not been substantiated when serial high-resolution anoscopy is compared with traditional expectant management.

OBJECTIVE

The aim of this study was to compare high-resolution anoscopy versus expectant management for the surveillance of anal intraepithelial neoplasia and the prevention of anal cancer.

DESIGN

This is a retrospective review of all patients who presented with anal squamous dysplasia, positive anal Pap smears, or anal squamous-cell cancer from 2007 to 2013.

SETTING

This study was performed in the colorectal department of a university-affiliated, tertiary care hospital.

PATIENTS

Included patients had biopsy-proven anal intraepithelial neoplasia from 2007 to 2013.

INTERVENTIONS

Patients were treated with high-resolution anoscopy with ablation or standard anoscopy with ablation. Both groups were treated with imiquimod and followed every 6 months indefinitely.

MAIN OUTCOME MEASURES

The incidence of anal squamous-cell cancer in each group was the primary end point.

RESULTS

From 2007 to 2013, 424 patients with anal squamous dysplasia were seen in the clinic (high-resolution anoscopy, 220; expectant management, 204). Three patients (high-resolution anoscopy, 1; expectant management, 2) progressed to anal squamous-cell cancer; 2 were noncompliant with follow-up and with HIV treatment, and the third was allergic to imiquimod and refused to take topical 5-fluorouracil. The 5-year progression rate was 6.0% (95% CI, 1.5-24.6) for expectant management and 4.5% (95% CI, 0.7-30.8) for high-resolution anoscopy (p = 0.37).

LIMITATIONS

This was a retrospective review. There is potential for selection and referral bias. Because of the rarity of the outcome, the study may be underpowered.

CONCLUSIONS

Patients with squamous-cell dysplasia followed with expectant management or high-resolution anoscopy rarely develop squamous-cell cancer if they are compliant with the protocol. The cost, morbidity, and value of high-resolution anoscopy should be further evaluated in lieu of these findings.

Anal intraepithelial neoplasia: a single centre 19 year review

AIM

There is debate about whether the traditional three-tiered grading of anal intraepithelial neoplasia (AIN) should be replaced by a more reproducible two-tiered system. In this study, we review our experience with AIN to determine the most suitable classification system.

METHOD

We performed a retrospective review of all histological reports over a 19 year period. All specimens were graded on haemataloxin and eosin appearance and those with dysplasia had immunohistochemistry for p16 and Ki67 performed.

RESULTS

Cases included 25 condyloma acuminata, 11 dysplastic cases and 24 invasive squamous cell carcinomas. On review, 18 were classified as condyloma acuminata without dysplasia. Seven had AIN I, five had AIN II and six had AIN III when using a three-tiered system. All cases classified as dysplastic (n = 18) showed an increased proliferation index as measured by Ki67. p16 positivity was seen in all AIN III, two AIN II and none of the AIN I cases. Recurrence was not observed in any of the AIN I cases. Five of eleven AIN II and AIN III cases recurred or persisted at a similar, higher or lower grade. Both of the AIN II cases which recurred or persisted were p16 positive. None of the AIN II cases that were p16 negative recurred. Three of the p16-positive AIN III cases did not recur. None of the 18 AIN cases progressed to carcinoma.

CONCLUSION

The findings support the slow progression of AIN as described in the literature. In our small series, a two-tiered system with further subclassification of the traditional AIN II group using p16 appears to be clinically useful.

Anal Pap smears and anal cancer: what dermatologists should know

Squamous epithelial cells are susceptible to infection by the human papillomavirus. Infection of squamous epithelium with oncogenic human papillomavirus types is associated with development of dysplasia and potential malignant transformation. Historically, cervical cancer has been the most prevalent human papillomavirus-induced squamous neoplasia. However, because of widespread screening via Pap smear testing, rates of cervical cancer in the United States have decreased dramatically during the past 50 years. Rates of anal cancer, in contrast, have doubled during the past 30 years. The groups at highest risk for development of anal cancer are men who have sex with men, HIV-positive patients, and patients immunosuppressed as a result of solid-organ transplantation. By detecting dysplasia before it develops into invasive cancer, anal Pap smears may be a potentially useful screening tool for anal cancer, particularly in individuals known to be at increased risk. However, at this time, sufficient data supporting the benefit of anal Pap smear screening are lacking. With insufficient evidence, no national health care organizations currently recommend the use of anal Pap smears as a routine screening test, even among high-risk groups.

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.

Comparable performance of conventional and liquid-based cytology in diagnosing anal intraepithelial neoplasia in HIV-infected and -uninfected Thai men who have sex with men

BACKGROUND

Anal cytology has increasingly been used to screen for anal intraepithelial neoplasia (AIN) among men who have sex with men (MSM) at increased risk for anal cancer. Use of liquid-based cytology has been reported to reduce fecal and bacterial contamination and air-drying artifact compared with conventional cytology. Costs associated with liquid-based cytology, however, may limit its use in resource-limited settings.

METHODS

Anal swab samples were collected from MSM participants and used to prepare conventional and liquid-based cytology slides. Abnormal conventional cytology results triggered referral for high-resolution anoscopy and biopsy. Agreement between the 2 cytology techniques and the positive predictive value ratios of histology confirmed AIN were calculated.

RESULTS

Among 173 MSM, abnormal anal cytology was identified in 46.2% of conventional and 32.4% of liquid-based slides. The results agreed in 62.4% of cases with a κ value of 0.49 (P < 0.001). HIV-infected MSM had a 3.6-fold increased odds of having discordant anal cytology results (95% confidence interval: 1.6 to 7.8; P = 0.001) compared with HIV-uninfected MSM. Histological AIN 2 and 3 were identified in 20 MSM. The positive predictive value ratios and 95% confidence interval indicated no difference between the 2 techniques.

CONCLUSIONS

Conventional anal cytology may be a preferred option for resource-limited settings given comparable performances to liquid-based cytology for the detection of AIN, although the agreement between the 2 techniques was lower among HIV-infected MSM. Due to high prevalence of abnormal anal cytology and AIN, health systems should prepare adequate infrastructure for high-resolution anoscopy services and AIN treatment.

p16 is superior to ProEx C in identifying high-grade squamous intraepithelial lesions (HSIL) of the anal canal

Although the incidence of human papillomavirus (HPV)-associated anal neoplasia is increasing, interobserver and intraobserver reproducibility in the grading of biopsy specimens from this area remains unacceptably low. Attempts to produce a more reproducible grading scheme have led to the use of biomarkers for the detection of high-risk HPV (HR-HPV). We evaluated the performance of standard morphology and biomarkers p16, ProEx C, and Ki-67 in a set of 75 lesions [17 nondysplastic lesions, 23 low-grade squamous intraepithelial lesions (LSIL)/condyloma, 20 high-grade squamous intraepithelial lesions (HSIL), 15 invasive squamous cell carcinomas] from the anal and perianal region in 65 patients and correlated these findings with HPV subtype on the basis of a type-specific multiplex real-time polymerase chain reaction assay designed to detect HR-HPV. A subset of cases with amplifiable HPV DNA was also sequenced. HSIL was typically flat (15/20), and only a minority (4/20) had koilocytes. In contrast, only 1 LSIL was flat (1/23), and the remainder were exophytic. The majority of LSIL had areas of koilocytic change (20/23). HR-HPV DNA was detected in the majority (89%) of invasive carcinomas and HSIL biopsies, 86% and 97% of which were accurately labeled by strong and diffuse block-positive p16 and ProEx C, respectively. LSIL cases, however, only infrequently harbored HR-HPV (13%); most harbored low-risk HPV (LR-HPV) types 6 and 11. Within the LSIL group, p16 outperformed ProEx C, resulting in fewer false-positive cases (5% vs. 75%). Ki-67 was also increased in HR-HPV-positive lesions, although biopsies with increased inflammation and reactive changes also showed higher Ki-67 indices. These data suggest that strong and diffuse block-positive nuclear and cytoplasmic labeling with p16 is a highly specific biomarker for the presence of HR-HPV in anal biopsies and that this finding correlates with high-grade lesions.

Anal warts and anal intradermal neoplasia

For the last five millennia we have been dealing with the annoyance of verrucas. Anogenital human papillomavirus (HPV) infection is the most common sexually transmitted disease in the United States and is increasing in incidence. As in other gastrointestinal conditions, HPV infection can lead to a stepwise transition from normal cells to dysplastic cells and then to invasive anal cancer. Knowledge of the natural history of HPV infection, risk factors, diagnostic tools, and therapeutic methods gives us the tools to adequately prevent, evaluate, treat, and counsel our patients. In this review, the authors detail the diagnosis, management, and treatment of anal condyloma and anal intraepithelial neoplasia with a focus on prevention, early detection, and treatment using current data and technology.

Comparison of the performance of anal cytology and cervical cytology as screening tests

Cervical cytology screening has a long history and has successfully reduced the impact of cervical cancer in many countries. Anal cytology is a relative newcomer and anal screening is currently offered in only a few centres around the world. Many questions need to be answered before anal screening is more widely adopted. While there are many similarities between cervical and anal squamous cell carcinoma, there are also important differences: differences in the prevalence of disease, in the ‘at-risk’ target populations and possibly in the robustness of the reference standard of biopsy. The performance of cytology as a screening test in the literature varies widely but it is essential to understand that some of this variability is due to differences in the definitions of key parameters in the various studies. For cervical screening, estimates of sensitivity have ranged from 19% to 94% and specificity from 94% to 98%. For anal screening, data are fewer and more limited. Estimates of the sensitivity of anal cytology in men who have sex with men and HIV-positive populations have ranged from 55% to 87% and specificity from 37% to 76%. Ultimately, rather than comparing anal with cervical cytology, it may be more helpful to assess the value of anal cytology independently through well designed trials.

Variabilidade interobservadores no diagnóstico de lesões precursoras do câncer anal: estudo do cenário habitual

OBJETIVO: Analisar a variabilidade interobservadores no diagnóstico de lesões precursoras do câncer anal no cenário mais comum de um serviço constituído por patologistas sem experiência prévia no diagnóstico destas lesões. MÉTODOS: Quinhentas e duas lâminas histopatológicas com espécimes anais retirados de 372 pacientes HIV-positivos e HIV-negativos foram analisadas no Departamento de Patologia da Fundação de Medicina Tropical do Amazonas por três patologistas com ampla experiência no diagnóstico de doenças tropicais e infecciosas, mas sem experiência prévia importante no diagnóstico de lesões precursoras do câncer anal. As leituras individuais de cada patologista foram comparadas com a que se seguiu a diagnóstico de consenso em microscópio de ótica compartilhada. Os diagnósticos individuais foram confrontados com os de consenso mediante análise da estatística kappa. RESULTADOS: A concordância absoluta entre cada diagnóstico individual e o de consenso correspondente foi ruim (kappa=-0,002). Considerando os resultados apenas positivos ou negativos para lesões intraepiteliais escamosas anais, obteve-se concordância regular entre os observadores (kappa=0,35), enquanto que a concordância foi moderada quando os resultados histopatológicos foram considerados positivos ou negativos para lesão intraepitelial de alto grau ou câncer (kappa=0,52). CONCLUSÃO: A variabilidade interobservadores no diagnóstico histopatológico do câncer anal e de suas lesões precursoras entre patologistas sem grande experiência na área, apesar de experts em outras, é tal que os diagnósticos neste campo e neste cenário comum devem sempre ser de consenso.

SHIRAZ: an automated histology image annotation system for zebrafish phenomics

Histological characterization is used in clinical and research contexts as a highly sensitive method for detecting the morphological features of disease and abnormal gene function. Histology has recently been accepted as a phenotyping method for the forthcoming Zebrafish Phenome Project, a large-scale community effort to characterize the morphological, physiological, and behavioral phenotypes resulting from the mutations in all known genes in the zebrafish genome. In support of this project, we present a novel content-based image retrieval system for the automated annotation of images containing histological abnormalities in the developing eye of the larval zebrafish.

Management of anal squamous intraepithelial lesions

Anal squamous intraepithelial lesions include both low-grade squamous intraepithelial lesions (LSIL) and high-grade squamous intraepithelial lesions (HSIL) and are caused by chronic infection with the human papillomavirus (HPV). The disease is increasing in both incidence and prevalence, especially among patients with the following risk factors: homosexual men, acquired or iatrogenic immunosuppression, and presence of other HPV-related diseases. Although the natural history of the disease is unknown, there is significant evidence that untreated HSIL progresses to squamous cell carcinoma in 11% of patients and in up to 50% of patients with extensive disease and immunosuppression. Anal cytology and reflex HPV DNA testing are used to screen for disease, particularly among patients with the aforementioned risk factors. Evaluation of the patient should include physical examination and high-resolution anoscopy (HRA) to evaluate for disease above and below the dentate line. Intervention is warranted and this can be achieved in many ways. The treatment option associated with the best outcomes is ablation directed with HRA, which can be performed in the office or in the operating room with minimal morbidity. This strategy is effective in patients with both low-volume and high-volume disease and is associated with a malignant progression rate of 0.4% in patients with treated HSIL.

Management of anal squamous intraepithelial lesions

Anal squamous intraepithelial lesions include both low-grade squamous intraepithelial lesions (LSIL) and high-grade squamous intraepithelial lesions (HSIL) and are caused by chronic infection with the human papillomavirus (HPV). The disease is increasing in both incidence and prevalence, especially among patients with the following risk factors: homosexual men, acquired or iatrogenic immunosuppression, and presence of other HPV-related diseases. Although the natural history of the disease is unknown, there is significant evidence that untreated HSIL progresses to squamous cell carcinoma in 11% of patients and in up to 50% of patients with extensive disease and immunosuppression. Anal cytology and reflex HPV DNA testing are used to screen for disease, particularly among patients with the aforementioned risk factors. Evaluation of the patient should include physical examination and high-resolution anoscopy (HRA) to evaluate for disease above and below the dentate line. Intervention is warranted and this can be achieved in many ways. The treatment option associated with the best outcomes is ablation directed with HRA, which can be performed in the office or in the operating room with minimal morbidity. This strategy is effective in patients with both low-volume and high-volume disease and is associated with a malignant progression rate of 0.4% in patients with treated HSIL.

Radiation therapy of recurrent anal squamous cell carcinoma in-situ: a case report

Introduction

High-grade anal intraepithelial neoplasia, also referred to as anal squamous carcinoma in-situ, or Bowen's disease of the anus, make up less than 1% of all digestive system cancers in the United States. The treatment of choice is surgical resection with anal mapping. However, this disease often recurs or persists, requiring additional surgery for these patients. This can compromise the anal sphincter leading to leakage. In this case report, we discuss the efficacy of radiation therapy as a modality to treat post-excisional recurrent Bowen's disease, which may prevent sphincter compromise, leading to improved quality of life.

Case presentation

An 84-year-old Caucasian woman presented with post-excisional persistent/recurrent squamous cell carcinoma in-situ. The initial lesion measured 3 cm in diameter on the right lateral side of the anal margin. A standard surgery consisting of wide local excision with anal mapping was performed. The margins were clear and our patient was followed up. Our patient recurred with a 1.2 × 0.8 cm lesion on the left anal verge extending to the anal canal. A biopsy along with mapping was done, and 2 of the 17 mapping specimens were positive for carcinoma in-situ, one in the anal canal. Due to the location of the positive anal mapping, and in order to prevent sphincter compromise on re-excision, our patient was offered definitive radiation therapy. Two years after radiation therapy, our patient showed no signs of recurrent disease and had good sphincter control.

Conclusion

Although the main treatment modality for treating persistent/recurrent Bowen's disease is surgery, an alternative approach using external beam radiation for CIS may be enough to provide a cure for some patients with recurrent disease.

Performance of anal cytology in a clinical setting when measured against histology and high-resolution anoscopy findings

OBJECTIVES

The success of cervical cytology in screening for cervical neoplasia has led to the concept of anal cytology screening for anal neoplasia. Our objective is to study the performance of anal cytology as a screening tool.

DESIGN

We assessed anal cytology against histology and high-resolution anoscopy in a clinical setting.

METHODS

Anal pap test was obtained prior to high-resolution anoscopy examinations and biopsies. The results were analysed against a number of patient variables.

RESULTS

From 395 individuals (93% men), 584 anal pap tests were obtained. HIV status was positive in 212 (54%) and negative in 156 (39%) individuals. On the basis of 288 histology results, the sensitivity of anal cytology to detect disease was 70% [95% confidence interval (CI) 64-75], whereas the specificity was 67% (95% CI 38-88). For high-grade disease (anal intraepithelial neoplasia 2/3), sensitivity of anal cytology was 81% (95% CI 70-90), and the negative predictive value was 85% (95% CI 76-92). Sensitivity was dependent on the area of disease (86% for two or more quadrants vs. 69% for one or more quadrants, P = 0.002) and HIV positivity (76% in HIV positive vs. 59% in HIV negative, P = 0.009). Amongst HIV-positive patients, the sensitivity was 90% when CD4 cell count was 400 cells/microl or less compared with 67% when CD4 cell count was above 400 cells/microl (P = 0.005).

CONCLUSION

Anal cytology performs similar to cervical cytology in a clinical setting. Sensitivity of anal smear is dependent on the area (quadrants) of disease present. Sensitivity of anal cytology is enhanced when CD4 cell count is less than 400 cells/microl in HIV-positive men. Our results may explain the variable sensitivity reported in the literature.

Screening anal dysplasia in HIV-infected patients: is there an agreement between anal pap smear and high-resolution anoscopy-guided biopsy?

PURPOSE

The purpose of this study was to analyze the agreement between anal Pap smear and high-resolution anoscopy-guided biopsy in diagnosing anal dysplasia in HIV-infected patients.

METHODS

We conducted cross-sectional analysis of HIV-infected patients receiving anal dysplasia screening as part of routine care. Agreement between measures was estimated by weighted kappa statistics, using a three-tiered cytologic and histologic grading system (normal, low-grade dysplasia, and high-grade dysplasia). Estimates of sensitivity, specificity, and predictive values were calculated using a two-tiered cytologic and histologic grading system ("without dysplasia" and "with dysplasia of any grade"). Estimates were also calculated for the detection of high-grade dysplasia.

RESULTS

During a one-year period, 222 patients underwent 330 anal Pap smears followed by high-resolution anoscopy-guided biopsies. There were 311 satisfactory Pap smears with concurrent biopsies. Considering histology the standard, the frequency of anal dysplasia was 46%. Kappa agreement between anal Pap smear and biopsy was 0.20. For detection of anal dysplasia of any grade, anal Pap smear showed sensitivity of 61%, specificity of 60%, positive predictive value of 56%, and negative predictive value of 64%. For high-grade dysplasia, anal Pap smear showed sensitivity of 16% and specificity of 97%.

CONCLUSION

Anal Pap smears alone were not sensitive enough to rule out anal dysplasia. We recommend that high-resolution anoscopy-guided biopsy be incorporated as a complementary screening test for anal dysplasia in high-risk patients. Following baseline high-resolution anoscopy, these individuals could be followed with serial anal cytology to dictate the need for future high-resolution anoscopy-guided biopsies.

Sensibilidade e especificidade da citologia anal com escova no diagnóstico das lesões clínicas provocadas pelo papilomavírus humano, comparando uma com duas coletas

OBJETIVO: comparar os resultados da coleta única com duas amostras para avaliar se haverá melhora da sensibilidade e especificidade do exame. MÉTODO: Foram 112 doentes masculinos HIV-positivo com doença anal pregressa ou atual pelo Papilomavírus humano (HPV). As lesões HPV induzidas foram observadas em 58 deles. Colhemos material do canal anal utilizando duas escovas (cytobrush) Comparamos estatisticamente os resultados da primeira amostra com a soma das duas coletas. RESULTADOS: dos 58 doentes com lesões clínicas, a primeira amostra confirmou a doença em 40 (69%) e a soma das duas coletas revelou lesões em 51 (88%). Os resultados mostraram sensibilidade de 69% com a primeira coleta e 88% quando somadas as duas amostras. Essa diferença foi confirmada estatisticamente. A especificidade foi menor para as duas amostras, porém sem diferença estatística. CONCLUSÃO: Concluímos que a sensibilidade foi maior e a especificidade foi semelhante quando os resultados foram obtidos com a somação das duas amostras da citologia anal.

Improved screening for anal neoplasia by immunocytochemical detection of minichromosome maintenance proteins

PURPOSE

Early detection of anal intraepithelial neoplasia (AIN) and anal squamous cell carcinoma (SCC) by screening will improve clinical outcome. Assessment of anal cytology samples using routine Papanicolaou testing suffers from shortcomings in sensitivity and/or specificity, suggesting that screening tests based on biomarkers may be of value. We tested the suitability in this context of minichromosome maintenance (MCM) proteins, accurate markers of the deregulated cell cycle entry that characterizes malignancy and premalignancy.

EXPERIMENTAL DESIGN

We undertook an initial immunohistochemical study of 54 anal tissue samples and validated our findings using an independent prospective cohort study of 235 anal cytology samples from 144 subjects.

RESULTS

In the progression from normal anal epithelium through AIN to SCC, there was increasing expression of MCM2 and MCM5, including in the superficial epithelial third, the source of the majority of cells collected by anal swab. The median labeling indices (LI) for MCM2 and MCM5 in the superficial third of AIN2/3 and SCCs combined were 90.2% and 84.0%, respectively. MCM LIs in the superficial layers were significantly greater than LIs for Ki67, an alternative marker of cell cycle entry (P<0.0001). By immunocytochemistry using a mixture of anti-MCM2 and anti-MCM5 antibodies, immunopositive cells were readily identified in anal cytology samples, even at low magnification. MCM testing showed sensitivity for AIN2/3 of 84% (95% confidence interval, 75,93) and for AIN1/viral changes of 76% (68, 84), with overall specificity (for any lesion) of 77% (64, 90).

CONCLUSIONS

MCMs are promising biomarkers for improving detection of AIN and SCC in anal cytology samples.

[Anal and anal margin tumors]

Tumors of the anal canal and anal margin are rare. They may raise specific problems for the pathologist. Benign tumors mainly consist of condylomas, cloacogenic polyps and fibro-epithelial polyps. Cancers are infrequent and consisted of well-differentiated squamous cell carcinoma, or poorly differentiated basaloid squamous cell carcinoma. The other malignant tumors are very rare.

P16 and Ki67 Immunostains Decrease Intra- and Interobserver Variability in the Diagnosis and Grading of Anal Intraepithelial Neoplasia (AIN)

BACKGROUND

Significant variation is reported in the diagnosis of HPV-associated AIN. We previously observed that band-like positivity for p16 in >90% of contiguous cells coupled with Ki67 positivity in >50% of lesional cells is strongly associated with high grade AIN. This study was undertaken to determine if addition of p16 and Ki67 immunostaining would reduce inter- and intraobserver variability in diagnosis and grading of AIN.

DESIGN

H&E stained slides of 60 anal biopsies were reviewed by three pathologists and consensus diagnoses were achieved: 25 negative, 12 low (condyloma and/or AIN I) and 23 high (9 AIN II and 14 AIN III) grade lesions. The H&E stained slides were diagnosed independently by three additional ("participant") pathologists. Several weeks later they re-examined these slides in conjunction with corresponding p16 and Ki67 immunostains.

RESULTS

Addition of p16 and Ki67 immunostains reduced intra- and interobserver variability, improved concurrence with consensus diagnoses and reduced two-step differences in diagnosis. Negative and high grade AIN diagnoses showed the most improvement in concurrence levels.

CONCLUSION

Addition of p16 and Ki67 immunostains is helpful in the diagnosis and grading of AIN.

Anal intraepithelial neoplasia and other neoplastic precursor lesions of the anal canal and perianal region

Anal cancer is rare and this helps to explain why anal pre-neoplastic conditions are poorly understood, especially with regard to their natural history and management. Anal intraepithelial neoplasia is closely linked to human papillomavirus infection and is particularly common in homosexuals and in immunosuppressed patients, especially those with HIV/AIDS. The high regression rates of low-grade anal intraepithelial neoplasia may simply reflect inconsistent pathologic reporting. Higher grades of anal intraepithelial neoplasia may remain static for long periods of time in immunocompetent patients, but those with HIV/AIDS show early and rapid malignant transformation. In general, most anal pre-neoplastic conditions are best diagnosed by biopsy and treated by surgical excision, although local recurrence is a problem. In anal Paget's disease, it is important to ascertain, at the time of diagnosis, whether it is due to a primary in-situ apocrine-type of neoplasia of the anus or if the disease is secondary to an invasive primary carcinoma of the rectum.

Intraoperative High-Resolution Anoscopy: A Minimally Invasive Approach in the Treatment of Patients with Bowen's Disease and Results in a Private Practice Setting

Anal intraepithelial neoplasia III (AIN III) is a risk factor for anal cancer with poor curative results and high morbidity. High-resolution anoscopy (HRA) is a minimally invasive means of identifying and treating AIN III early. We retrospectively reviewed HRA in the treatment of AIN III in a community setting. From January 2002 through November 2005, 76 patients with AIN III diagnosed by anal Pap smear, colposcopy, or biopsy underwent HRA for diagnosis and treatment. Twenty-one patients with AIN III on initial HRA underwent follow-up HRA for reassessment and treatment at 6 months. Recurrence/persistence of disease was recorded and compared with patient characteristics. Of 21 patients with repeat HRA, four were HIV-negative and 17 were HIV-positive. Twelve of 21 (57%) had intraanal recurrence/persistence; nine of 21 (43%) had no AIN III. Eleven (92%) with recurrence were HIV-positive; one (8%) was HIV-negative. Three (75%) HIV-negative patients had no recurrence/persistence; one of four (25%) had recurrence; and 11 of 17 (65%) HIV-positive patients had persistence of disease. HRA is an alternative tool to treat AIN III and can be performed in a community setting yielding results comparable to the university setting. As the prevalence of AIN III increases, it will be more important for community surgeons to treat AIN III with HRA.

Screening HIV-infected individuals for anal cancer precursor lesions: a systematic review

Individuals with human immunodeficiency virus (HIV) infection are at increased risk for human papillomavirus-related squamous cell cancer of the anus. Screening HIV-infected patients for squamous cell cancer of the anus and human papillomavirus-related anal dysplasia may prevent excess morbidity and mortality. We have conducted a systematic review of the indirect evidence in the literature regarding the utility of anal Papanicolau (Pap) smear screening of HIV-infected individuals in the highly active antiretroviral therapy era. Although there are no published studies evaluating the efficacy of anal Pap smear screening for preventing squamous cell cancer of the anus or anal intraepithelial neoplasia, we reviewed data regarding the burden of disease, anal Pap smear sensitivity and specificity, the prevalence of anal dysplasia, and 1 cost effectiveness study. The available evidence demonstrates that HIV-infected individuals have an increased risk for squamous cell cancer of the anus and anal intraepithelial neoplasia. This review identifies important areas for further study before routine anal Pap smear screening can be recommended.

DNA methylation in anal intraepithelial lesions and anal squamous cell carcinoma

PURPOSE

Anal intraepithelial neoplasia is associated with human papillomavirus infection and may progress to invasive squamous cell carcinoma (SCC), which is increasing in immunocompromised patients. We hypothesize that anal intraepithelial neoplasia is associated with abnormal DNA methylation and that detection of these events may be used to improve screening programs.

EXPERIMENTAL DESIGN

Seventy-six patients were identified who underwent anal cytology screening and subsequent biopsy at our institution between 1999 and 2004. The specimens from these patients included 184 anal biopsies [normal, n = 57; low-grade squamous intraepithelial lesion (LSIL), n = 74; high-grade squamous intraepithelial lesion (HSIL), n = 41; and invasive SCC, n = 12] and 37 residual liquid-based anal cytology specimens (normal, n = 11; LSIL, n = 12; HSIL, n = 14). The methylation status of the following genes was determined for each biopsy and cytology sample using real-time methylation-specific PCR: HIC1, RASSF1, RARB, CDKN2A, p14, TP73, APC, MLH1, MGMT, DAPK1, and IGSF4.

RESULTS

Methylation-specific PCR analysis of biopsy samples revealed that DNA methylation was more common in SCC and HSIL than LSIL and normal mucosa. Specifically, methylation of IGSF4 and DAPK1 was prevalent in SCC (75% and 75% of cases, respectively) and HSIL (59% and 71%, respectively) but was absent in LSIL and normal biopsy samples. Methylation profiles of cytologic samples were similar to those found in the biopsy samples.

CONCLUSIONS

Aberrant DNA methylation is a frequent event in anal HSIL and SCC. Methylation of IGSF4 and DAPK1 is specific for HSIL and SCC, and may serve as a useful molecular biomarker.

Screening Methods for High-Grade Dysplasia in Patients with Anal Condyloma1

Human papilloma virus (HPV) is one of the most common sexually transmitted diseases in the United States. HPV infection can cause anal condylomas and is a risk factor for dysplasia. High-grade dysplasia may progress to squamous cell carcinoma. Currently, biopsy and histological examination are required to grade dysplasia. The purpose of this study is to determine whether anal cytology, morphological characteristics, and/or the presence of high-risk oncogenic HPV-types are effective noninvasive methods to detect high-risk anal condylomas.

PATIENTS AND METHODS

From November 2003 to June 2004, all patients with anal condyloma were prospectively evaluated for anal cytology, high-risk oncogenic HPV-types, and tissue biopsies. The Bethesda classification system was used to classify cytologic findings and histological examination, which were grouped as high-risk (HRL) and low-risk (LRL) lesions. Histology results served as true disease for all comparisons.

RESULTS

Forty-seven patients with anal condyloma were studied; 43 (91.5%) were men, and the mean age was 39 +/- 11 years. Histology showed 19 (40.5%) patients with HRL, and 28 (59.5%) patients with LRL. Cytology correctly identified 8 patients with HRL and 27 patients with LRL (sensitivity 42% and specificity 96%). High-risk oncogenic HPV-types were found in 84.2% of HRL and 39.3% of LRL (P = 0.0029). Combining cytology with oncogenic HPV-testing, the sensitivity of detecting HRL increased to 89%, and specificity decreased to 42%.

CONCLUSION

Anal cytology alone is not accurate for detecting HRL in patients with anal condylomas. Combining oncogenic HPV-testing with cytology is more sensitive in detecting HRL in patients with anal condyloma, and therefore, a more effective screening tool.

Interobserver agreement in the interpretation of anal intraepithelial neoplasia

BACKGROUND

Anal carcinoma incidence is increasing, and is highest among men with human immunodeficiency virus (HIV) infection who have sex with men. Anal carcinoma and anal intraepithelial neoplasia (AIN) are ascertained on tissue histology, but requires invasive procedures. Screening for AIN using anal cytology was suggested. The authors evaluated agreement on cytologic and biopsy specimens from HIV-positive men undergoing anal carcinoma screening.

METHODS

One hundred twenty-nine HIV-positive men with a history of anal-receptive intercourse underwent anal cytology, anoscopy, and biopsy. Four pathologists independently assessed cytology and biopsy specimens and reached consensus for discordant cases.

RESULTS

Each pathologist evaluated 120 cytology and 155 biopsy specimens. The weighted kappa value for overall agreement was 0.54 (95% confidence interval [CI], 0.49-0.59) for cytology specimens and 0.59 (95%CI, 0.55-0.63) for biopsy specimens. The median kappa values for pairwise agreement among pathologists and for agreement with consensus were, respectively, 0.69 and 0.77 for cytology and 0.66 and 0.75 for biopsy. At least 3 pathologists were in agreement for 92 (76.7%) cytology and 134 (86.5%) biopsy specimens. Reliability for the Bethesda classification system was at least moderate, except for the cytologic category of atypical squamous cells of undetermined significance (kappa = 0.12). Fourteen of 29 (48.3%) cytology specimens and 36 of 47 (76.6%) biopsy specimens with consensus interpretation of high-grade squamous intraepithelial lesions (HSIL) were interpreted originally as HSIL by > or = 3 pathologists. The kappa value for agreement with consensus distinguishing HSIL from non-HSIL ranged from 0.55 to 0.88 for cytology specimens and from 0.76 to 0.94 for biopsy specimens.

CONCLUSIONS

Agreement for cytologic and biopsy interpretations was generally at least moderate. Nevertheless, these results supported the need for disease indicators with greater reliability.

Anal intraepithelial neoplasia

Background

Anal intraepithelial neoplasia (AIN) is believed to be a precursor of anal squamous cell cancer and its incidence is rising in high-risk groups, particularly those infected with the human immunodeficiency virus (HIV). The natural history of AIN is unclear and management strategies are lacking.

Methods

This review is based on a literature search (Medline and PubMed) with manual cross-referencing of all articles related to AIN.

Results and conclusions

The aetiology of AIN is intricately linked with human papilloma viruses. The pathological processes involved in the progression of AIN are becoming clearer but the natural history, particularly the rate of progression to invasive cancer, remains unknown. There is no standard management for AIN and this is mainly due to difficulties in both diagnosis and treatment. A variety of treatment options have been tried with varying success. Surgery is associated with significant recurrence, particularly in HIV-positive patients. Non surgical approaches with imiquimod, photodynamic therapy and vaccination are appealing, and further work is required. Long-term follow-up of these patients is essential until the natural history of AIN becomes clearer.