Histologic, nuclear DNA, and human papillomavirus studies of cervical condylomas

How should we grade CIN?

How should we grade CIN? The grading of cervical intraepithelial neoplasia (CIN) is problematic. CIN represents a morphological continuum, but biopsies displaying this lesion are classified into two (e.g. Bethesda) or three grade categories, sometimes with poor reproducibility. There are also difficulties in reliably distinguishing low-grade CIN from its reactive simulants. Because of problems with inter- and intra-observer disagreement in the grading of CIN and the diagnosis of low-grade lesions, three expert contributions were commissioned to address the question 'how should we grade CIN?'.

Oncogenic human papillomaviruses and ploidy in cervical lesions

AIM

To compare ploidy measurements obtained on tissue sections of selected low and high grade squamous intraepithelial lesions containing oncogenic HPV (types 16, 18 or 33) detected by in situ hybridisation (ISH) or PCR.

METHODS

DNA ploidy was assessed by image cytometry after Feulgen staining of contiguous serial sections of eight lesions exhibiting atypical squamous cells or squamous atypia and 53 low and 63 high grade squamous intraepithelial lesions in which HPV had been detected by ISH or PCR.

RESULTS

Aneuploidy was strongly associated with the presence of oncogenic HPV, being detected in 50% of lesions with squamous atypia and 75.5% of the low and 95.2% of the high grade squamous intraepithelial lesions. The multiploid profile was highly associated with high grade lesions and with the pattern of HPV DNA integration.

CONCLUSIONS

The presence of aneuploidy is strongly suggestive of the presence of oncogenic HPV types. Combining the detection of HPV by ISH and PCR with DNA image cytometry may provide the pathologist and the physician with important prognostic information about low grade lesions, especially when these lesions have a multiploid DNA profile and contain oncogenic HPV.

Comparison of four non-radioactive and 35S-based methods for the detection of human papillomavirus DNA by in situ hybridization

Human papillomavirus DNA was detected in 40 condylomatous lesions of various sites (vulva, cervix, larynx, penis and anus) by in situ hybridization using 35S-labelled probes and four non-radioactive probes to compare the various sensitivities of these techniques on the same material (formalin-fixed and paraffin-embedded sections). Radioactive probes yielded 28 positive results out of 40 (70%). Sulphonated probes (HybriCyte kit) also gave 28 positive results with a fine pattern of hybridization grains and equal sensitivity to 35S-labelled probes. Biotinylated and digoxigenin-labelled probes gave analogous results (25 positive reactions with the PathoGene kit, 26 with the Viratype kit, and 25 with digoxigenin-labelled probes) but are slightly less sensitive than radiolabelled and sulphonated probes especially when the signal is weak.

Pathobiology of papillomavirus-related cervical diseases: prospects for immunodiagnosis

In recent years, the relationship between human papillomaviruses (HPV) and genital neoplasia has been explored intensively, and a molecular basis for the role of HPV in the genesis of these diseases has been convincingly demonstrated. These findings have provided justification for efforts to apply this molecular information to the early detection and possible prevention of HPV-related neoplasia. The technology of detecting viral nucleic acids in genital fluids brought with it initial hopes that it would serve to identify women at risk for having or developing precancers or cancers of the cervix. Subsequent studies, however, have demonstrated limitations of the technology for predicting future disease. Recently, molecular immunology has complemented these prior efforts, with the intent to identify serological indices of exposure to HPV and perhaps delineate individuals at risk. The molecular basis for this approach, its limitations, and future prospects for immunodiagnosis are the subject of this review.

Influence of human papillomavirus on DNA ploidy determination in genital condylomas

It has been reported that deoxyribonuclease (DNAse) treatment does not destroy viral DNA, but it does digest native nuclear DNA. To determine what effect, if any, papillomavirus infection has on DNA ploidy values of genitourinary condylomas, DNA was measured with and without DNAse exposure in seven urethral condylomas, shown by prior in situ hybridization to contain abundant human papillomavirus types 6 and 11. Normal human skin was used as a negative control. Consecutive paraffin-embedded tissue sections were stained according to Feulgen before and after DNAse treatment. The DNA was measured by image analysis. In control tissue, DNAse obliterated DNA, and the Feulgen reaction was negative. In six of seven condylomas the DNA content was reduced, but a measurable Feulgen reaction was still present in isolated cells. In the seventh case there were no significant changes in the histograms. This observation strongly suggests that the presence of human papillomavirus has a significant effect on measurements of DNA ploidy in genital condylomas and, by implication, possibly also in other tissues containing the virus. Possible mechanisms are discussed.

Role of human papillomavirus in the pathogenesis of genital tract warts and cancer

During the last decade a large number of clinical, epidemiological, and experimental studies have elucidated the role of HPV in the pathogenesis of anogenital cancer. Although the clinical and epidemiological studies have been criticized for a variety of technical and design shortcomings, for the most part they have independently reached the same conclusion--there is a strong association between the presence of specific types of HPV and the development of anogenital cancer. Similarly, laboratory studies clearly indicate that specific types of HPV act in concert with other cellular changes to transform a variety of cell types in vitro, including human cervical epithelial cells. Over the next decade the challenge is twofold. First we need to define precisely the mechanisms by which HPV either by itself or in concert with other factors, acts to transform anogenital epithelial cells. These studies will, it is hoped, identify important cofactors in the transformation process and determine the role of host immunity. Second, we need to determine the clinical applicability of the association between HPV and anogenital cancer. Large clinical studies will determine whether HPV testing of asymptomatic patients facilitates the detection of patients at risk for developing cervical cancer and whether the presence of a specific type of HPV in a cervical cancer actually affects a patient's prognosis. As the answers to these and other questions become available, we will be in a better position to assess the clinical importance of the associations between HPV and anogenital cancer.

Basic concepts and practical applications of recombinant DNA techniques in detection of human papillomavirus (HPV) infection. Review article

Recent studies on the role of infectious agents in the pathogenesis of malignancy have demonstrated a strong association between HPV and several human benign and malignant epithelial neoplasms. There are 60 distinct types of HPV, of which HPV 16, 18, 31, 33, 35 and 39 have been associated with squamous cell neoplasia of the genital tract. Rapid progress in the field of recombinant DNA technology with the availability of specific probes has enabled the detection of HPV genomic sequences in characteristic HPV lesions. In addition, HPV sequences have been found in malignant squamous cell lesions, and even in normal tissues lacking the morphologic signs of HPV infection. Currently, hybridization analysis of the nucleic acid is the most reliable method for diagnosis of HPV infections, also permitting the genotyping of these viruses. A variety of hybridization procedures have been developed with different sensitivities and specificities. Despite the divergent technical modifications, however, all hybridization tests working according to the same basic principles. The double helix of DNA composed of two complementary polynucleotide chains can be opened by heating or by increasing pH. Cooling of the two strands allows reassociation. Labeled HPV DNA or RNA probe hybridizes with the complementary sequences allowing the detection of HPV sequences in the samples. Hybridization assays can be conducted under conditions in which virtually all HPVs will be detected, but not specifically typed (low stringency) or under conditions in which the type can be identified (high stringency). Widely divergent results have been reported both in prevalence of HPV infection and distribution of different HPV types in the genital tract. These discordant results have been explained on the basis of sampling effects, differences in histopathological diagnosis, geographical variations in HPV types and interlaboratory variation in HPV detection and typing techniques. In this review the various procedures for detecting HPV sequences by hybridization and related techniques are shortly described.

Human papillomaviruses: are we ready to type?

The issue of determining which human papillomavirus (HPV) is present in a clinical specimen (typing specimens for HPVs) is receiving attention because HPVs cause condyloma acuminata and are associated with the continuum of disease which ranges from dysplasia to invasive genital cancer. Morphological inspection of precancerous lesions is not sufficient to determine which lesions will progress and which will not. A number of research tools based primarily on deoxyribonucleic acid hybridization have been developed. These permit identification and typing of HPV in genital tract scrapings or biopsies. Some HPV types (e.g., HPV-16 and HPV-18) have been identified in high-grade dysplasias and carcinomas more commonly than other types (e.g., HPV-6) and have been designated "high risk" types for cervical cancer. Thus, the question arises whether HPV typing would improve patient management by providing increased sensitivity for detection of patients at risk or by providing a prognostic indicator. In this review, the available typing methods are reviewed from the standpoint of their sensitivity, specificity, and ease of application to large-scale screening programs. Data implicating HPVs in the genesis of genital tract cancers are reviewed, as is the association of specific HPV types with specific outcomes. We conclude that there is currently no simple, inexpensive assay for HPV types, although such assays may be developed in the future. Analysis of the typing data indicates that, while HPV types can be designated high risk and low risk, these designations are not absolute and thus the low-risk group should not be ignored. In addition, interpretation of the data is complicated by finding high-risk types in individuals with no indication of disease. Insufficient data exist to indicate whether knowledge of the presence of a given HPV type is a better prognostic indicator than cytological or histological results. Thus, more research is needed before it can be determined whether typing information will augment the method currently in use for deciding treatment regimen and whether it warrants widespread use.

Squamous papillary neoplasia of the adult upper aerodigestive tract

Selected papillary squamous tumors of the upper aerodigestive tract (UADT) mucosa in adult patients do not have well-defined histologic criteria and the clinical behavior is poorly understood. To better characterize this spectrum of neoplasms, UADT papillary neoplasms were evaluated by routine histology, determination of cellular DNA content using Feulgen-stained tissue sections, and the typing of human papillomavirus (HPV) by in situ hybridization. Solitary papillomas were studied in two patients; there was no recurrence in either case, both had normal DNA content, and one was typed as HPV-6 while the other was typed as HPV-11. Seven adult patients with recurrent papillomatosis and at least one biopsy with dysplasia/atypia were identified (mean age at diagnosis, 13.3 years; mean age at last contact, 42.7 years). Six of seven patients had abnormal DNA cellular content in foci of epithelial atypia. In all biopsies evaluated, the papillomas of the seven patients were consistently typed as either HPV-6 or HPV-11. Six patients with malignant papillary neoplasms also had abnormal DNA cellular content, but none revealed evidence of HPV type 6, 11, 16, or 18 by in situ hybridization of tissue sections. In many of the recurrent papillomas, the degree of epithelial atypia encountered was pronounced and was commonly misdiagnosed as carcinoma in situ or papillary carcinoma. The aneuploid DNA content of these foci of atypia reflected the abnormal cellular appearance and partially explained the overdiagnosis of malignancy. However, none of the seven patients were treated for malignant disease and none progressed to invasive carcinoma, with an average follow-up period of almost 30 years. We conclude that histologic and cytologic atypia in HPV-containing papillomatosis may be appreciable. The aneuploid DNA content may represent premalignant conditions and the patient may be at an increased risk for the subsequent development of squamous cancer. However, none of the seven patients with recurrent papillomatosis developed any evidence of malignancy. In addition, none of the patients with papillary carcinomas had previous recurrent papillomatosis.

Cancer of the cervix and the papilloma viruses

Squamous cancer of the cervix depends upon infection by Human Papilloma Virus (HPV), of which there are many strains. Some are more dangerous than others and they appear to compete with each other for "territory". The prospective use of vaccines and antiviral agents for HPV infection could disturb the balance of this ecosystem. This study derives the expressions for the prevalences of the different strains at equilibrium. The important parameters of these expressions are 1) the rate of change of sexual partner, 2) infectiousness on contact, and 3) the rates at which an infectious/immune phase decays to a non-infectious/immune phase, and then towards partial or full susceptibility to re-infection. The responses to changes in these parameters are investigated. Analysis shows that the balance between competing strains is locally and precariously stable; it can survive moderate inter-strain variations of the transmission and decay parameters; but larger differences, whether natural or artificially induced, can result in the rapid elimination of the disadvantaged strain. This might be exploited in a preventive programme. Conversely, if a harmless strain were eliminated, the harmful strains would fill the territorial gap, and the incidence of cervical cancer might increase.

Simultaneous presence of herpes simplex and human papilloma virus sequences in human genital tumors

Herpes simplex virus (HSV) and human papillomavirus (HPV) sequences were analyzed in tumors of the female lower genital tract, by probing DNA from 13 intraepithelial and 30 invasive neoplastic lesions with radiolabelled HPV-16 and HPV-18 DNA as well as cloned fragments of HSV-2 DNA. Careful removal of stromal tissue from the pathological specimens allowed authentic tumor DNA to be processed. Normal genital tissue obtained from the patients and genital condylomata were included as internal controls. The presence of HPV-16 or 18 DNA was detected in 12/13 (92.3%) intraepithelial neoplasms and in 16/30 (53.3%) invasive carcinomas. No significant difference was detected in titer or frequency of antibodies to HPV group-specific antigen in sera from patients and controls. Hybridization to BgIII N fragment of HSV-2 DNA was detected in 4/13 (30.8%) intraepithelial neoplasms and 4/30 (13.3%) invasive carcinomas but in none of the control tissues. All the 8 samples harboring HSV-2 homologous sequences were also positive for HPV, supporting the hypothesis of a synergistic association between the 2 viruses. The hybridization analyses performed to study c-myc involvement in genital oncogenesis did not reveal c-myc amplification in either invasive or pre-invasive lesions.

Topographic study of cervical condyloma and intraepithelial neoplasia

In this study of 101 cervical conization specimens, the location and the size of condyloma and intraepithelial neoplasia (dysplasia and carcinoma in situ) were mapped using the last endocervical gland as the marker for the original squamocolumnar junction. Condylomatous changes were identified in 85% of cervices affected by the intraepithelial neoplasia, and were in direct contact with 68% of intraepithelial neoplasms. The proximal location of intraepithelial neoplasia in relation to the condyloma can be explained by the occurrence of neoplasia just proximal to the condyloma and subsequent expansion of neoplasia towards the cervical canal. This study adds topographic evidence linking cervical condyloma to the development of intraepithelial neoplasia.

Assessment of precancerous lesions of the uterine cervix for evidence of human papillomavirus infection: a histological and immunohistochemical study

Cervical biopsies obtained by colposcopic direction from 358 women were histologically examined for squamous dysplasia (cervical intra-epithelial neoplasia; CIN) and human papillomavirus (HPV) infection. Of the 358 biopsies, 136 were stained by an immunoperoxidase method using an antiserum against genus-specific (common) antigen of bovine papillomavirus. HPV antigens were detected in 40% of biopsies showing definite histological evidence of HPV effect, and in 7.9% and 2.6% of those with possible or no HPV effect, respectively. HPV effect was commonly seen in association with CIN. The frequency of histological evidence of HPV effect and positive immunoperoxidase staining decreased with increasing grades of CIN. HPV antigen was found in 57% of areas of HPV change with minor atypia, 34% of zones of CIN I and in only 8% of zones of CIN II. No antigenic staining or definite histological evidence of HPV effect was observed within areas of CIN III. Antigen was generally confined to the nuclei of superficial koilocytes, cells with lesser degrees of perinuclear clearing and parakeratotic cells. These results how a strong association between HPV infection and precancerous lesions of the uterine cervix and are consistent with the hypothesis that production of the HPV structural antigen requires a high degree of squamous cell maturation. The immunoperoxidase findings and the histopathological observations support the view that HPV change and dysplasia are part of a morphological continuum in which the cytopathic effect of HPV is expressed mainly in lower grades of dysplasia.

Involucrin expression in cervical intraepithelial neoplasia: a critical evaluation

Involucrin is a keratinocyte envelope protein precursor which is synthesized at an early stage of differentiation in normal squamous epithelium. Recent studies suggest that this protein may be a marker for neoplastic epithelium. To address this issue, we analyzed involucrin expression in 105 biopsies containing 119 areas of normal, condylomatous, and neoplastic epithelium. Overall, 88, 75, and 55% of condylomata, well-differentiated CIN, and poorly differentiated CIN (carcinoma in situ) contained positive staining for involucrin. Excluding lesions with severe inflammation, 100, 88, and 55% of these lesions, respectively, were positive. Staining patterns in neoplastic lesions differed from those in the normal epithelium and condylomata; the staining in CIN tended to be focal, and intensity of staining varied widely from cell to cell in all layers of the epithelium. In high grade CIN, staining correlated with increases in cell size and cytoplasmic differentiation. These studies suggest that involucrin will not differentiate between lesions of low versus high risk for progressing to invasive carcinoma. However, the patterns of involucrin expression confirm the marked differences in patterns of cellular differentiation between classical condylomata and CIN.

Immunocytochemical localization of human papilloma virus and cytomorphologic correlation in smears and biopsies of cervical flat condylomata

The cytomorphologic features in cervical biopsies and smears associated with human papilloma virus antigen (Ag) expression as demonstrated by immunoperoxidase staining techniques are presented. There was good concordance between cytology and biopsy results with respect to immunoperoxidase staining for human papilloma virus Ag. Cytomorphologic scoring of low-grade lesions (cervical intraepithelial neoplasias, grades O and I) showed atypical mitoses, macronucleated koilocytes, superficial cell keratohyaline granules, and multinucleation to be more frequent in Ag+ biopsy specimens. Chronic inflammation was more evident in Ag- biopsy specimens (P less than 0.05). Parakeratosis was more frequent in Ag+ cytologic specimens. Koilocytosis was not a reliable indicator of Ag expression in either preparation. Human papilloma virus (HPV) Ag testing by immunoperoxidase techniques appears to be a useful adjunct for screening low-grade atypias of the cervix.

Oral condyloma planus (hairy leukoplakia) among homosexual men: a clinicopathologic study of thirty-six cases

Thirty-six cases of oral condyloma planus (hairy leukoplakia) occurring in homosexual men are reported. The average age is 36.6 years, with a range from 24 to 51 years, and the disorder exhibits a predilection for the fourth decade. More than 86% of the cases are localized to the tongue (72% lateral border, 14% ventral surface). Microscopically, surface candidiasis could be detected with periodic acid-Schiff staining in 88% of the instances. Parakeratosis with koilocytotic atypia was the characteristic histologic finding; however, comparison with twenty-five cases of leukoplakias exhibiting parakeratosis and twenty-five cases of candidiasis among heterosexual individuals disclosed that koilocytotic changes are not specific for condyloma planus. Follow-up data were obtained in thirty-two cases with a mean of 11 months. During this period six patients died or were hospitalized with a diagnosis of acquired immunodeficiency syndrome.

Immunophenotypes of lymphocytes in prospectively followed up human papillomavirus lesions of the cervix

From 1981 286 women were prospectively followed up for a mean (SD) of 16 (14) months for established infection with human papillomavirus (HPV) with or without coexistent cervical intraepithelial neoplasia (CIN). The in situ immunocompetent cell infiltrates in 263 cervical punch biopsy specimens from these women were phenotypically identified by the avidinbiotin peroxidase complex (ABC) technique using monoclonal antibodies Leu-10, OKT-3, OKT-4, and OKT-8. Leu-10+ B lymphocytes far outnumbered the OKT-3+ T lymphocytes in all types of HPV lesions (flat, inverted, and papillomatous condylomas of the cervix). The ratio of OKT-4+ to OKT-8+ (T helper to T suppressor cells) was slightly reduced in HPV lesions with more severe CIN and correlated positively with the intensity of the immunocompetent cell infiltrate. The ratio of OKT-4+ to OKT-8+ cells was highest in the 47 (28.8%) patients with HPV lesions that regressed during follow up, somewhat lower in the 85 (52.1%) with persistent lesions, and lowest in the 31 (19.1%) with lesions showing clinical progression. The results are discussed in terms of the proposed immune surveillance functions attributed to immunocompetent cells in situ according to the mucosal associated lymphatic tissue (MALT) concept. The conclusion drawn is that a dynamic balance between the immunoregulatory cells and their subtypes is a prerequisite for the proper handling of intracellular infections of the mucosa, including that with HPV.

Herpes simplex virus type 2 and human papillomavirus type 16 in cervicitis, dysplasia and invasive cervical carcinoma

Sera and biopsies of cervical lesions from 55 women with benign or malignant disease were analyzed for evidence of infection with herpes simplex virus type 2 (HSV-2) or human papillomavirus (HPV). In addition, information regarding known risk factors for cervical cancer was obtained by interview. The sera were tested for HSV-2 antibodies and the biopsies were tested for HPV or HSV DNA sequences by Southern blot hybridization. HSV-2 sequences were detected in 2/13 (15%) invasive neoplasms and in 1/12 (7%) benign lesions. Under non-stringent conditions of hybridization, reactions with HPV DNA were detected in biopsies of 2/17 (12%) inflammatory lesions, 6/12 (50%) intraepithelial neoplasms and 13/20 (65%) invasive neoplasms. All but one of the positive biopsies of invasive cancer, but only 4/11 biopsies of non-invasive lesions, contained HPV-16 DNA as determined by stringent hybridization conditions. Women with cervical cancer possessed the risk factors associated with the disease. Cigarette smoking and the presence of HPV-16 DNA were the most prominent risk factors. No evidence of an interaction between HSV-2 and HPV-16 was found among the cases of invasive cervical cancer.

The koilocyte and cervical intraepithelial neoplasia: time-trend analysis of a recent decade

To determine whether the role of the human papillomavirus in the development of cervical intraepithelial neoplasia has changed recently, cervical biopsy specimens from the years 1972 and 1982 were reviewed to compare the frequency of diagnosis of human papillomavirus-associated koilocytosis in patients with suspected cervical intraepithelial neoplasia. No significant difference was found in the frequency of koilocytosis in biopsy specimens with cervical intraepithelial neoplasia between the years, koilocytosis being present in about half of the cases of cervical intraepithelial neoplasia during both years. In each year koilocytosis was more common in grades 1 and 2 lesions. Koilocytotic atypia without cervical intraepithelial neoplasia also was present in a relatively constant proportion of cases over the decade (8.0% and 6.5%). The average patient age was younger in 1982 than in 1972 (27.6 versus 32.6 years), but analysis of patients by age groups again showed no significant difference in the occurrence of koilocytosis. This study suggests that the relative importance of human papillomavirus in the evolution of cervical intraepithelial neoplasia has remained unchanged in the recent past.

Papillomavirus in cervical condylomas with and without associated cervical intraepithelial neoplasia

The aim of this study was to analyze the cytohistologic features of cervical condylomas with respect to the presence of associated cervical intraepithelial neoplasia (CIN) and to evaluate whether or not the prevalence of virus antigen, as detected by immunologic staining with peroxidase-antiperoxidase technique, varies with the histologic appearance of the lesions. In a series of 94 histologically confirmed condylomas of the cervix, almost half (43) had features of CIN grades 1 and 2, corresponding to mild and moderate dysplasia. The prevalence of papillomavirus antigen decreased markedly as the features of associated dysplasia became more severe. The antigen prevalence was 82% in pure condylomas, 32% in condylomas with CIN 1, and 0% in condylomas with CIN 2. The evidence that virus production decreased as the lesion became more severe does not preclude papillomavirus etiology for the CIN lesions. Cells transformed by papillomavirus may be expected to cease production of virus particles even as they continue to harbor the viral genome.