Human papillomavirus DNA determination of anal condylomata, dysplasias, and squamous carcinomas with in situ hybridization

History of High-Resolution Anoscopy

High-resolution anoscopy (HRA) is a form of low-resolution anal microscopy currently utilized in the screening and management of anal squamous dysplasia. No randomized controlled trials, national or international guidelines exist on the use of HRA for this purpose. Much of our understanding of this entity has been adapted from the literature on cervical squamous dysplasia, including the technique of HRA itself. Epidemiologic evidence has shown that the prevalence and incidence of anal dysplasia is highest in HIV-positive populations. The history of this technique parallels the evolution of our understanding of anal dysplasia. To understand the history of the use of HRA and its place in the screening and management of anal squamous dysplasia, we discuss key advances in the understanding of human papillomavirus-related squamous dysplasia. We begin with early reports in the field establishing the link between this virus and squamous dysplasia, through the marked increase in anal cancer seen with the onset of the HIV epidemic, the identification of relevant populations at risk, the performance of the test itself, to its use today.

HPV-related squamous neoplasia of the lower anogenital tract: an update and review of recent guidelines

Squamous cell carcinomas of the lower anogenital tract that are related to human papillomavirus (HPV) infection represent a significant disease burden worldwide. The diagnosis and management of their noninvasive precursors has been the subject of extensive study and debate over several decades, accompanied by an evolving understanding of HPV biology. Recent new consensus recommendations for the pathologic diagnosis of these precursor lesions were published in 2012, the result of the Lower Anogenital Squamous Terminology project cosponsored by the College of American Pathologists and the American Society for Colposcopy and Cervical Pathology. Most salient among the new guidelines are the recommendation to switch to a 2-tiered nomenclature (high-grade squamous intraepithelial lesion and low-grade squamous intraepithelial lesion) rather than the traditional 3-tiered "intraepithelial neoplasia" terminology, and the recommendation to expand use of the immunohistochemical marker p16 to distinguish between low-grade squamous intraepithelial lesion and high-grade squamous intraepithelial lesion/intraepithelial neoplasia 2. The goals of the project were to align diagnostic terminology with our knowledge of HPV biology, increase reproducibility, consolidate diverse systems of nomenclature, and ultimately better determine a patient's true cancer risk. The clinical guidelines for screening and management of cervical intraepithelial neoplasia have also been recently updated, most notably with a lengthening of screening intervals. In this review, we focus on the new guidelines put forth for pathologic diagnosis of HPV-related anogenital neoplasia, with discussion of the evidence behind them and their potential implications. We also provide an update on relevant biomarkers, clinical recommendations, and the newest developments relating to cervical neoplasia.

Clinicopathological analysis of basal cell carcinoma of the anal region and its distinction from basaloid squamous cell carcinoma

Basal cell carcinoma of the anal region is rare and morphologically difficult to distinguish from basaloid squamous cell carcinoma, particularly on biopsies. This distinction has therapeutic and prognostic implications. We reviewed morphological features of 9 basal cell carcinomas and 15 basaloid squamous cell carcinomas from the anal region diagnosed during 1993-2011 and determined the utility of Ber-EP4, BCL2, TP63, CK5/6, CDKN2A, and SOX2 as diagnostic tools. Immunostains were scored in a semi-quantitative manner (1+-1-10%, 2+-11-50%, 3+->50%). All basal cell carcinomas were located in the perianal region, while all basaloid squamous cell carcinomas originated in the anal canal/anorectum. Nodular subtype of basal cell carcinoma was the most common subtype. Retraction artifact was the only significant distinguishing histological feature of basal cell carcinoma compared with basaloid squamous cell carcinoma (88% vs 26%; P=0.04). Atypical mitoses were more common in basaloid squamous cell carcinomas (71% vs 11%; P=0.05). An in situ component was only present in basaloid squamous cell carcinomas, and was noted in 6/15 cases. Basal cell carcinomas had 2-3+ Ber-EP4 (basal cell carcinoma 100% vs basaloid squamous cell carcinoma 40%; P<0.001) and BCL2 immunoreactivity (basal cell carcinomas 100% vs basaloid squamous cell carcinoma 33%; P<0.001). Diffuse CDKN2A and SOX2 expression was seen only in basaloid squamous cell carcinomas (basal cell carcinoma 0% vs basaloid squamous cell carcinoma 93%; P<0.001). There was no difference in TP63 and CK5/6 expression. Perianal location, retraction artifact, and lack of atypical mitoses are histological features that help distinguish basal cell carcinoma from basaloid squamous cell carcinoma. An in situ component, when present, supports the diagnosis of basaloid squamous cell carcinoma. Immunostains are extremely helpful as diffuse Ber-EP4 and BCL2 expression is a feature of basal cell carcinoma and basaloid squamous cell carcinoma is typified by diffuse CDKN2A and SOX2 expression.

HPV and precancerous lesions of anal canal in women: systematic review

OBJECTIVE

The infection caused by human papillomavirus (HPV) in the anogenital area is considered the most common sexually transmitted infection in the world. Although anal cancer is relatively uncommon in the general population, there has been a significant increase in incidence in recent years. In this review, we focused on research on anal lesions in women.

METHOD

Research on HPV and precancerous lesions of the anal canal was examined by a systematic literature review in the Cochrane Centre of Brazil, where 1,734 publications were identified in the databases Scielo Brazil, Pubmed, Lilac, Medline, and Old Medline, for the period 1966 to 2010. We selected two papers, published in 1994 and 2009, based on the inclusion-exclusion criteria.

RESULTS

The first paper refers to the study of the anal canal in HIV-negative women with previous genital pathology and its relationship to the presence of HPV, and the other compares two groups of women who are HIV+ and HIV- and its relationship with anal disease and HPV.

CONCLUSION

The existence of previous genital neoplasia associated with HPV promotes the development of anal lesions, especially in younger patients, and a poor immune status contributes to the appearance of this pathologic finding.

Epidermoid carcinoma of the anal canal

Anal cancers are rare tumors with only an expected 4000 new diagnoses in 2005. The majority of these are epidermoid or squamous cell cancers. Despite the rarity of this disease, great advances have been made in its understanding and treatment. The human papillomavirus (HPV), immunosuppression for solid organ transplantation, the human immunodeficiency virus (HIV), and sexual practices are changing the demographics of the disease from elderly women to young men who have sex with men and young women infected with HPV and HIV. The treatment of these malignancies was radically changed with Dr. Nigro's description in 1974 of the use of a nonoperative treatment strategy. Today, radiochemotherapy represents first-line therapy and the role of surgery has been largely relegated to that of salvage therapy for treatment failures of nonoperative management.

Immunohistochemical Expression of p16 and Ki-67 Correlates With Degree of Anal Intraepithelial Neoplasia

Anal intraepithelial neoplasia (AIN) is a human papilloma virus related lesion. It has been shown that infection with high-risk human papilloma virus results in up-regulation of p16 and increased cellular proliferation. The objective of this study is to correlate p16 expression and cellular proliferation measured by Ki-67 staining with the degree of dysplasia in the anal canal and to determine the efficacy of these markers in diagnosing high-grade AIN. Seventy-five anal specimens from 55 patients (37 men; 18 women; mean age: 48 y; median: 44 y; range 25 to 96 y) were studied including 35 normal/reactive lesions, 23 low-grade AIN (AIN I and condyloma), and 17 high-grade AIN (AIN II and III). Immunostaining for p16 and Ki-67 was performed. Expression of p16 in AIN correlated with that of Ki-67 (P<0.001). High-grade AIN often demonstrated p16 staining in more than one-third of the thickness of the epithelium in a diffuse/continuous fashion. p16 expression in low-grade AIN was often restricted to the lower 1/3 of the epithelium and/or was focal and discontinuous. The expression of both p16 and Ki-67 correlated with the degree of dysplasia (P<0.01). When positive p16 staining was defined as the presence of diffuse/continuous staining in more than one-third of the thickness of epithelium, the sensitivity, specificity, and accuracy of p16 as a marker for diagnosing high-grade AIN were 76%, 86%, and 84%, respectively. When positive Ki-67 staining was defined as the presence of nuclear staining in more than 25% of the cells in more than one-third of the thickness of epithelium, the sensitivity, specificity, and accuracy of Ki-67 as a marker for diagnosing high-grade AIN were 71%, 84%, and 83% respectively. Both p16 and Ki-67 are reliable markers for diagnosing high-grade AIN.

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.

Carcinoma of the anal canal

Despite the rarity of carcinoma of the anal canal, remarkable progress has been achieved during the past 30 years in understanding its pathogenesis and improving treatment. Largely because of the rigorous collection of data and the treatment of patients in clinical trials, it is now widely accepted that the majority of cases are caused by human papillomavirus and can be cured by combination therapy. Concomitant treatment with external-beam radiation therapy and chemotherapy with fluorouracil and mitomycin represents the standard approach to combination treatment. Appropriate cytologic screening of high risk populations and the integration of platinum compounds into treatment regimens will most likely reduce mortality from this disorder even further.

Current therapy for recurrent and extensive anal warts

PURPOSE

This study was undertaken to review the literature regarding the current therapy for recurrent and extensive anal warts.

METHODS

The available treatments for condyloma acuminatum are reviewed with particular regard to their efficacy for recurrent or extensive anal lesions. Topical agents, surgical methods, and the use of interferon are discussed. Treatment of anal warts in the immunocompromised patient is also addressed.

CONCLUSIONS

Although small lesions may be responsive to repeated applications of topical agents, more extensive lesions require surgical or combination treatment. Intralesional interferon may be a useful adjunct to surgical methods to decrease recurrence.

Anogenital warts in children

Fourteen children presenting with anogenital (AG) warts and their close family members were studied; 28.6 and 8.3% of presenting children and other child household members, respectively, had non-genital cutaneous warts; 42.8% of children with AG warts had one or more adult household member with common hand warts. Fifty per cent of all mothers had subclinical cervical papilloma virus (PV) infection; only one male adult had subclinical PV infection of the penis without concurrent AG warts. Of the children with AG warts 42.8% had one or more adult household member with AG warts. Human papilloma virus (HPV) deoxyribonucleic acid (DNA), type 6/11 most frequently, was detected in 38.5% AG wart biopsies from children, and 67% AG wart biopsies from adults. HPV 31/33/35 was detected in 28.5% of cervical preneoplasias and type 6/11 in the one case of subclinical PV infection of the penile shaft. Detection of HPV types 6/11, 16/18, or 31/33/35 in AG warts in children was significantly associated with vertical (from an HPV-infected maternal birth canal during vaginal delivery) or sexual transmission of these warts (Fisher exact probability P = 0.031).

Molecular and serological studies of human papillomavirus among patients with anal epidermoid carcinoma

Certain types of human papillomavirus (HPV) are associated with anogenital carcinomas, including carcinomas of the anal canal. Whereas several serological studies have found an association between papillomavirus antibody responses and cervical carcinoma, the antibody response against papillomavirus antigens among patients with anal carcinoma has not been investigated. The present study has examined the antibody responses to a panel of papillomavirus-derived antigens and compared the serological profile with the histology and HPV carrier state of the tumor, as well as with the stage and prognosis of the disease. Sera from 64 patients with anal cancer and from 79 healthy blood donors were studied in ELISA for the presence of IgA and IgG antibodies to 5 previously described HPV16-derived synthetic peptide antigens. Serum IgA antibodies to a peptide antigen derived from the E2 region of HPV16 were found in 89% of patients with anal cancer as compared to 24% of controls (p = 0.0001). The IgA reactivity to the 4 other antigens showed only low and non-significant increases in mean titer. Serum IgG responses were similar among patients and controls. Among patients who had progressive disease, 21/21 were seropositive for IgA anti-E2 at diagnosis, as compared to 36/43 patients who were in remission after a mean follow-up of 41 months (p = 0.05). Forty-seven cases of anal carcinoma were also studied for the presence of HPV by in situ hybridization using a probe mix of 7 anogenital HPV types. Sixteen patients (35%) carried HPV in their anal cancer and one patient had an HPV-positive benign lesion adjacent to the tumor. Patients with HPV-carrying anal cancer were significantly younger than those with HPV-negative anal cancers (mean age: 57 and 68 years, respectively, p = 0.03). No differences in seroreactivity or HPV carrier state were seen depending on the stage or histological type of the tumor.

Influence of fixation on human papillomavirus DNA detection in frozen and embedded paraffin lesions by in situ hybridization with biotinylated probes

Series of frozen or paraffin-embedded tissues from various body sites, taken from non-immunosuppressed or immunosuppressed patients with persistent papilloma lesions were examined for the presence of group specific antigen from human papillomavirus (HPV) by indirect immunofluorescence or HPV DNA by in situ hybridization with biotinylated probes. We have shown that it is possible to detect HPV DNA after fixation of tissues in neutral formalin, Bouin's or Baker's solution. However, the sensitivity was reduced as compared to frozen tissues. The HPV DNA was detected in nuclei of heavily infected epithelial cells such as plantar or hand warts or in dispersed cells containing high copy numbers of HPV DNA from lesions such as squamous cell carcinomas or keratoacanthomas. In premalignant or malignant lesions of both immunosuppressed or non-immunosuppressed patients, HPV DNA was rarely detected after fixation. HPV types commonly described for skin and genital samples were identified in non-immunosuppressed patients, whereas in transplant recipients oncogenic HPV type 16 was identified in benign warts as well as in premalignant or malignant lesions. Positive reactions with several HPV types were more frequent in lesions from grafted patients than from the normal population. Virus antigen was detectable more frequently in frozen sections than in fixed tissues. Our findings indicate that in situ hybridization is an appropriate and rapid technique to study the presence of HPV infection. However, numerous controls are needed to avoid misinterpretations.

Comparison of HPV detection in parallel biopsies and cervical scrapes by PCR

PCR was used to detect HPV DNA in cervical scrapes of 23 women with cervical cancer. Compared with PCR-assisted HPV DNA detection in parallel biopsies, the sensitivity was 81% and the specificity 100%. We conclude that cervical scrapes can be used for detection of HPV DNA in women with cervical cancer.

Epstein-Barr virus-associated primary B-cell lymphoproliferative disorder of the cerebellum in an immune competent man

BACKGROUND

The role of the Epstein-Barr virus (EBV) in lymphoproliferative lesions has been widely accepted. Most of these lesions occur in patients who have deficiencies in their immune status. Lymphomatoid granulomatosis (LG) is a lymphoproliferative disorder originally characterized as an angiocentric, necrotizing, pleomorphic infiltrate of mononuclear cells. The etiology of LG is unknown. It was originally hypothesized that LG may represent an unusual lymphoid response to an infective organism, possibly EBV.

METHODS

Tissues from a previously healthy 60-year-old, healthy white man with primary cerebellar lymphomatoid granulomatosis were examined for the presence of EBV by nucleic acid hybridization.

RESULTS

The original LG lesion was a polyclonal B-cell proliferation that contained detectable amounts of EBV. Peripheral blood leukocytes were negative for EBV by the same assay. After an 18-month remission, a tumor reappeared near the site of the primary lesion, which had the histologic appearance of a lymphoma. The cells showed restricted clonality and contained a similar amount of EBV-related DNA as the original lesion. Peripheral blood leukocytes at the time of recurrence were negative for EBV. The patient died approximately 2 months after the recurrent tumor was detected.

CONCLUSIONS

This case demonstrated the development of a primary cerebellar B-cell lymphoproliferative disorder, histologically identical to lymphomatoid granulomatosis, that transformed into a lymphoma. The original tumor and the subsequent lymphoma contained, on average, several copies of EBV-related DNA per cell. Despite an extensive survey of the patient, no immune deficit was detected. Interpretation of the literature with the results of this case suggest that this instance of primary cerebellar LG arose as a consequence of an unusual EBV-associated B-cell lymphoproliferation. It is suggested that EBV may be a significant factor in the initiation of the abnormal proliferations of T-cells or B-cells reported in this disorder.

Human papillomavirus detection in cervical dysplasias or neoplasias and in condylomata acuminata by in situ hybridization with biotinylated DNA probes

Specimens from cervical dysplasias or carcinomas and genital condylomata acuminata were retrospectively analysed by in situ hybridization (ISH) with biotinylated DNA probes for human papillomavirus (HPV) types 6, 11, 16 and 18. In the control group no case was positive for HPV DNA. In mild/moderate dysplasias, 4 cases (14%) were positive for HPV 6 or 11 and 2 cases (7%), for HPV 16. In the severe dysplasia/in situ carcinoma group, 9 cases (31%) showed presence of DNA of HPV types 16 or 18. Six invasive carcinomas (20%) were positive for HPV type 16 or 18. Among condylomata acuminata, 22 cases (73%) were positive for HPV types 6 or 11. In all ISH-positive cases only one viral type was detected. No correlation between HPV DNA positivity and histological findings of HPV infection was observed. Although less sensitive than some other molecular biology techniques, in situ hybridization with biotinylated DNA probes proved to be simple and useful for detecting and typing HPV in samples routinely received for histopathological analysis.

Differing characteristics of human papillomavirus RNA-positive and RNA-negative anal carcinomas

Anal carcinomas were tested for the presence of human papillomavirus (HPV) RNA transcripts by in situ hybridization using 125I-labeled RNA probes. The HPV transcripts were detected in 73.2% of 41 nonglandular anal carcinomas but in none of six anal or 11 rectal adenocarcinomas. In anal nonglandular carcinomas, no difference in the percentage of tumors that were HPV RNA positive was observed between tumors classed as basaloid carcinomas or squamous cell carcinomas. Patients with HPV RNA-negative tumors were significantly older (9.2 years) than those with HPV RNA-positive tumors. Anal intraepithelial neoplasia Grade 3 in the surrounding epithelium was seen in 14 of 25 assessable HPV RNA-positive tumors and in none of nine assessable HPV RNA-negative tumors. Anal tumors may include two separate clinical and biologic groups distinguished by their dependence, or lack of dependence, on HPV RNA expression for maintenance of the neoplastic state.

Intraepithelial neoplasia of the anal canal in hemorrhoidal tissue: a study of 19 cases

The investigators report the clinical and pathologic features of 19 cases of intraepithelial neoplasia occurring in the anal canal mucosa of routinely excised hemorrhoidal tissue, a condition that has been infrequently described. The patients were 12 women and seven men having an age range of 21 to 74 years (mean, 48 years). Two patients had coexistent anogenital condylomata acuminata. Leukoplakia of the hemorrhoidal surface was noted in two patients. Intraepithelial neoplasia arose in the transition zone of the anal canal of 11 cases, in the squamous zone of three cases, and in both sites of five cases. All were high-grade intraepithelial neoplasms; one was classified moderate to severe dysplasia, 17 exhibited severe dysplasia/carcinoma in situ, and one contained microinvasive carcinoma. Both keratinizing and cloacogenic type neoplasms were observed. Associated koilocytotic atypia was identified in 16 cases (84%). In situ hybridization for human papillomavirus (HPV) messenger RNA demonstrated HPV RNA sequences in seven of nine neoplasms (78%) studied by that technique (five HPV type 16, one HPV type 18, and one coinfection with HPV types 6 and 18). Eighteen patients had no clinically evident recurrent or progressive disease at mean follow-up of 6.6 years. Residual/recurrent intraepithelial neoplasia was noted in one patient at 1, 2, 5, and 49 months posthemorrhoidectomy. Our data indicate that incidentally discovered high-grade intraepithelial neoplasia present in hemorroidal tissue is a clinically nonaggressive lesion frequently associated with HPV infection. Hemorrhoidectomy alone is curative in most cases.

Anorectal surgery in the HIV+ patient: update

Anorectal surgery in HIV+ patients historically has been viewed with a great deal of nihilism. Advances in medical therapy and better understanding of unique pathophysiologic processes have afforded the colorectal surgeon the ability to treat better and sometimes cure the anorectal complications of AIDS. We present a series of 75 consecutive surgical procedures (1-year accrual) on HIV+ (40) and CDC AIDS (22) patients. Surgical procedures, perioperative T cell counts, and outcome will be presented; 53 percent of procedures resulted in complete healing of anal wounds; 30 percent resulted in partial healing with symptomatic relief; 17 percent resulted in symptomatic relief or tissue diagnosis without appreciable wound healing. The healing rate was significantly higher in the HIV+ group (69 percent) compared to the AIDS group (26 percent). Perioperative T cell counts did not have predictive value on outcome. No patients suffered significant unexpected morbidity, mortality, or incontinence. Pathophysiologic mechanisms of several disease processes unique to HIV+ patients and data from our ongoing investigation using RNA hybridization are presented.

Anal human papillomavirus infection: a comparative study of cytology, colposcopy and DNA hybridisation as methods of detection

OBJECTIVE

To compare anal cytology, colposcopy and DNA hybridisation as methods of detecting anal HPV infection.

SUBJECTS AND DESIGN

Patients attending: (1) a genitourinary medicine (GUM) clinic with ano-genital warts; (2) a surgical out-patient department with anal fissure or haemorrhoids were examined for evidence of anal HPV infection.

RESULTS

Considering GUM clinic attenders, 17% (38/225) and 40% (90/225) had perianal or anal canal warts respectively. Colposcopic examination revealed anal acetowhite lesions without warts in 28% (63/225). Cytological evidence of HPV infection was found in 98%, 83%, and 90% of patients with anal canal warts, perianal warts and acetowhite lesions respectively. Anal intraepithelial neoplasia (AIN) was documented in 22% of patients with anal canal warts compared with 6% with perianal warts (p less than 0.01). HPV DNA was detected from the anal brushings of 71%, 50%, 32%, and 29% of patients with anal canal warts, perianal warts, acetowhite lesions and a normal anal examination respectively. HPV type 6/11 was detected in the majority of HPV positive samples. Considering surgical out-patient attenders with no history or signs of anal warts, 25% showed cytological evidence of anal HPV infection and HPV DNA was detected from anal brushings in 3% (2/71).

CONCLUSION

Anal examination with the colposcope is a useful method for detecting subclinical HPV infection. Anal cytology may prove helpful for detecting AIN, however, since koilocytosis was rarely seen, the specificity of the cytological criteria for anal HPV infection in the absence of AIN is uncertain. DNA analysis of anal brushings proved only moderately sensitive.

Human papillomavirus type 16 associated with oral squamous carcinoma in a cardiac transplant recipient

Human papillomavirus type 16 (HPV 16) has been associated with a variety of squamous carcinomas, particularly those involving the anogenital tract. The authors report the development of an oropharyngeal carcinoma in a 43-year-old man approximately 20 months after cardiac transplantation while he was on a maintenance regimen of cyclosporine A and prednisone. The carcinoma was resistant to treatment, and he died of complications related to metastatic disease 3 years posttransplantation. Molecular biologic studies using nonisotopic-labeled viral DNA probes were done. In situ hybridization demonstrated the presence of HPV 16 DNA in the tumor cells. DNA dot blot analysis confirmed the presence of multiple copies of HPV 16 DNA within the tumor cells and their absence from adjacent normal-appearing tissue. Southern blot analysis suggested that the HPV 16 DNA was integrated into the tumor cell genome. With increasing recognition of the carcinogenicity of HPV type 16 infection, a role for this virus in the development of squamous cell malignancies in immunosuppressed organ transplant recipients is likely to be noted with increasing frequency.

Alimentary tract cytopathology in human immunodeficiency virus infection: a review of experience in Los Angeles

In the past decade, over 100,000 cases of the acquired immunodeficiency syndrome (AIDS) have been reported in the United States. Conservative estimates suggest that 1.5 million people are infected with the human immunodeficiency virus (HIV), the etiologic agent of AIDS. Major metropolitan areas, such as Los Angeles, have experienced a rapid increase in the number of AIDS cases. At the Los Angeles County-University of Southern California Medical Center, we have gained significant insight into the cytologic findings associated with HIV infection. Based on our experience, we herein review the technical and morphologic evaluation of alimentary tract cytology specimens from this patient population.