Distribution and characterization of subtypes of penile intraepithelial neoplasia and their association with invasive carcinomas: a pathological study of 139 lesions in 121 patients

We are presenting the morphological features of 121 cases of atypical penile intraepithelial lesions. The term penile intraepithelial neoplasia (PeIN) was used to encompass all of them, and lesions were classified into 2 major groups, differentiated and undifferentiated. The latter was further divided in warty, basaloid, and warty-basaloid subtypes. Ninety-five cases were associated with invasive squamous cell carcinomas. Differentiated lesions predominated (68%), followed by warty-basaloid (14%), basaloid (11%), and warty (7%) subtypes. Multifocality was found in 15% of the cases. Differentiated lesions were preferentially located in foreskin, whereas warty and/or basaloid subtypes were more prevalent in the glans. The former lesions were preferentially seen in association with keratinizing variants of squamous carcinoma, whereas the latter subtypes were found mostly in conjunction with invasive warty, basaloid, and warty-basaloid carcinomas. Lichen sclerosus was present in 51% of cases of differentiated lesions and absent in warty and/or basaloid subtypes. In summary, PeIN can be classified into 4 distinctive morphological subtypes. The proper pathological characterization of these lesions may provide important clues to the understanding of the pathogenesis and natural history of penile cancer.     

Differentiated precursor lesions and low-grade variants of squamous cell carcinomas are frequent findings in foreskins of patients from a region of high penile cancer incidence

Oertell J, Caballero C, Iglesias M, Chaux A, Amat L, Ayala E, Rodríguez I, Velázquez E F, Barreto J E, Ayala G & Cubilla A L
(2011) Histopathology  58 , 925–933
Differentiated precursor lesions and low‐grade variants of squamous cell carcinomas are frequent findings in foreskins of patients from a region of high penile cancer incidence Aims: About 10–20% of all penile squamous cell carcinomas (SCCs) originate in the foreskin, but knowledge about preputial precursor and associated lesions is scant. The aims of the present study were to determine the prevalence of various precancerous and cancerous lesions exclusively affecting the foreskin, and to describe their pathological features. Methods and results: One hundred consecutive circumcision specimens from symptomatic patients living in a region of high penile cancer incidence were analysed. Clinical diagnoses included mostly phimosis and chronic balanoposthitis (40 and 35 cases, respectively), but also a tumour mass (11 cases). Histopathological lesions found included: squamous hyperplasia in 61 cases; lichen sclerosus in 53 cases; penile intraepithelial neoplasia (PeIN) in 30 cases (all differentiated PeIN, with two cases showing multicentric foci of basaloid and warty–basaloid PeIN); and invasive SCC in 11 cases (three usual, three pseudohyperplastic, two verrucous–pseudohyperplastic, and one case each of basaloid, papillary and mixed usual–basaloid carcinomas). Lichen sclerosus was present in all low‐grade SCC cases. Patients with no lesions were younger (mean age 44 years) than those with precursor lesions (mean age 54 years) or with invasive SCC (mean age 68 years). Immunohistochemistry for p16^INK4a was performed in 19 precancerous lesions. All differentiated PeINs (18 lesions) were negative, and one basaloid PeIN was positive. Conclusions: The frequent coexistence of lichen sclerosus, squamous hyperplasia, differentiated PeIN and low‐grade SCC suggests a common non‐human papillomavirus related pathogenic pathway for preputial lesions, and highlights the importance of circumcision in symptomatic patients for the prevention of penile cancer.     

Updates in the pathology of penile intraepithelial neoplasia

Penile intraepithelial neoplasia (PeIN) is the putative histologic precursor of penile squamous cell carcinoma. PeIN is classified into HPV-associated and HPV-independent (differentiated) (dPeIN). While HPV-associated PeIN is has been linked to the oncogenic effect of human papillomavirus (HPV), the HPV-independent pathway is driven by chronic inflammatory conditions. These two biologic pathways are associated with distinct histopathologic features. The most common morphologic patterns of HPV-associated PeIN are basaloid, warty, and mixed PeIN. DPeIN is the morphologic expression of HPV-independent PeIN. This review will focus on the epidemiological, etiologic, and pathogenetic aspects of PeIN, as well as the morphologic patterns of the two major categories of PeIN. Furthermore, recent 2022 WHO updates will be discussed.     

An overview of benign and premalignant lesions of the foreskin

The foreskin is a common surgical specimen encountered by the practising histopathologist. Therapeutic circumcisions are performed to treat both benign and neoplastic foreskin lesions. Penile intraepithelial neoplasia (PeIN) is the precursor lesion of penile squamous cell carcinoma (SCC). The World Health Organisation (WHO) classifies PeIN into two subtypes based on the association with Human Papillomavirus (HPV); these include differentiated and undifferentiated PeIN. These subtypes of PeIN can be differentiated by specific cytological and architectural characteristics. This review article will discuss these histological characteristics and highlight potential difficulties that may arise in diagnosing PeIN. Furthermore, it will also consider common benign and preneoplastic foreskin lesions that may be encountered when reporting the foreskin specimen.     

Advances in the pathology of penile carcinomas

The incidence of penile cancer varies from country to country, with the highest figures reported for countries in Africa, South America, and Asia and lowest in the United States and Europe. Causes of this variation are not clear, but they are thought to be related to human papillomavirus infection, smoking, lack of circumcision, chronic inflammation, and poor genital hygiene. Most penile tumors are squamous cell carcinomas, and a variegated spectrum of distinct morphologies is currently recognized. Each one of these subtypes has distinctive pathologic and clinical features. About half of penile carcinomas are usual squamous cell carcinomas, and the rest corresponds to verrucous, warty, basaloid, warty-basaloid, papillary, pseudohyperplastic, pseudoglandular, adenosquamous, sarcomatoid, and cuniculatum carcinomas. Previous studies have found a consistent association of tumor cell morphology and human papillomavirus presence in penile carcinomas. Those tumors composed of small- to intermediate-sized, basaloid ("blue") cells are often human papillomavirus positive, whereas human papillomavirus prevalence is lower in tumors showing large, keratinizing, maturing eosinophilic ("pink") cells. Human papillomavirus-related tumors affect younger patients, whereas human papillomavirus-unrelated tumors are seen in older patients with phimosis, lichen sclerosus, or squamous hyperplasia. This morphologic distinctiveness is also observed in penile intraepithelial neoplasia. The specific aim of this review is to provide a detailed discussion on the macroscopic and microscopic features of all major subtypes of penile cancer. We also discuss the role of pathologic features in the prognosis of penile cancer, the characteristics of penile precursor lesions, and the use of immunohistochemistry for the diagnosis of invasive and precursor lesions.     

Role of human papillomavirus in penile cancer,penile intraepithelial squamous cell neoplasias and in genital warts

Using PCR, the overall prevalence of human papillomavirus (HPV) DNA in penile carcinoma is about 40–45%, which is similar to the detection rate of HPV-DNA in vulvar carcinoma (50%). In analogy to vulvar cancer two different pathways of penile carcinogenesis seem to exist. In contrast to basaloid and warty penile cancers which are regularly HPV-associated (about 80–100%), only a part of keratinizing and verrucous penile carcinomas appear to be related with HPV (33–35%). Penile intraepithelial neoplasias comprising Bowen's disease, erythroplasia of Queyrat and bowenoid papulosis are precursor lesions of basaloid and warty carcinomas of the penis.Precursors of keratinizing carcinomas and verrucous carcinomas are not established. Whether lichen sclerosus and squamous-cell hyperplasia precede penile keratinizing carcinoma is a matter of discussion. Giant condylomata acuminata may precede the development of verrucous carcinomas in some cases. Since high risk HPVs are more frequently found in verrucous carcinomas than in giant condylomas, HPV typing may be a helpful diagnostic step to differentiate giant condyloma from verrucous carcinoma.     

Warty/basaloid penile intraepithelial neoplasia is more prevalent than differentiated penile intraepithelial neoplasia in nonendemic regions for penile cancer when compared with endemic areas: a comparative study between pathologic series from Paris and Paraguay

Penile squamous cell carcinoma shows an ample geographic variation in its prevalence with regions of low (North America, Europe, Japan, and Israel) and high (Africa, Asia, and South America) incidence. However, the geographic variation in the distribution of penile intraepithelial neoplasia is not well established. The aim of the present study was to compare the distribution of in situ and invasive lesions between geographic areas with low (France) and high (Paraguay) penile cancer incidence using a series of consecutive cases. The French series included 86 cases (57 in situ and 29 in situ + invasive squamous cell carcinoma), and the Paraguayan series, 117 cases (31 in situ and 86 in situ + invasive squamous cell carcinoma). Incidence of invasive squamous cell carcinoma in the overall samples was higher in the Paraguayan series (P < .00001). Comparing the Paraguayan and the French series, differentiated penile intraepithelial neoplasia was more prevalent in the former (65.0% versus 19.8%), whereas lesions showing warty and/or basaloid features predominated in the latter (35.0% versus 80.2%) to a significant level (P < .00001). This distinctive pattern of differential distribution was maintained when cases with associated invasive squamous cell carcinoma were excluded. The pattern of distribution of lichen sclerosus was also distinctive, with a significantly higher prevalence in the Paraguayan population when compared with the French series (32.5% versus 12.8%, P = .0015). In summary, there appears to be a distinctive distribution of penile precursor lesions depending on the geographic region in consideration. Penile intraepithelial neoplasia with warty and/or basaloid features predominated in low-incidence areas, whereas differentiated penile intraepithelial neoplasia was more prevalent in endemic regions for penile cancer. Further prospective studies in matched populations and from different geographic regions are needed to further clarify the reasons for this discrepancy.     

Diagnostic problems in precancerous lesions and invasive carcinomas of the penis

Penile precancerous and invasive lesions exhibit a variegated morphology. Although the diagnosis and classification of penile tumors is straightforward in most cases, a few entities are problematic, especially to pathologists from countries in which penile cancer is rarely encountered. The differential diagnosis of squamous hyperplasias from differentiated penile intraepithelial neoplasia or from extremely low-grade invasive neoplasms (eg, pseudohyperplastic and verrucous carcinomas) may be particularly difficult. Similarly, given the morphologic features shared by all verruciform tumors (ie, verrucous, warty, papillary, and cuniculatum carcinomas, along with giant condylomas), it is challenging at times to distinguish one from another. At the other end of the spectrum, because of their lack of differentiation, it is sometimes difficult to classify high-grade carcinomas, such as basaloid and sarcomatoid, which may have etiologic/prognostic implications. Penile mixed tumors, harboring more than 1 histologic subtype and grade, constitute a frequent finding in routine pathology. The recognition of distinctive morphologic patterns and histologic grades in these tumors is important because these features could be related to etiologic factors, such as human papillomavirus infection, or they could influence outcome. Penile tumors with glandular features (eg, adenosquamous and mucoepidermoid carcinomas), although rare, may be confused with the more common pseudoglandular (adenoid, acantholytic) variant of squamous cell carcinomas, their main mimicker. In this review we provide clues that may help in the differential diagnosis of these lesions.     

Epithelial lesions associated with invasive penile squamous cell carcinoma: a pathologic study of 288 cases

A heterogeneous spectrum of epithelial alterations and atypical lesions affect the squamous epithelium of penile mucosal anatomical compartments. Analogous to other genital sites, the terminology utilized to define the lesions is variable. The few pathologic studies of penile precancerous lesions are mostly related to carcinoma in situ and human papilloma virus (HPV), and the information on low-grade atypical lesions is limited. The objective of this study was to comprehensively describe the morphologic features of all epithelial alterations, benign and atypical, low grade and high grade, associated with invasive squamous cell carcinoma of the penis and to investigate their relation with each other and with subtypes of invasive carcinoma. We also propose herein a simple and reproducible nomenclature for penile precancerous abnormalities until more biological, molecular, or epidemiologic information on the lesions is available. Two hundred and eighty-eight penectomy and circumcision specimens with invasive squamous cell carcinoma were pathologically evaluated. Carcinomas were classified as usual, verrucous, papillary not otherwise specified, warty (condylomatous), basaloid, and mixed. Associated lesions were classified as squamous hyperplasia and squamous intraepithelial lesions of low and high grade (LGSIL and HGSIL). In LGSIL, atypia was confined to the lower third, and in HGSIL, atypical cells affected at least two thirds of the squamous epithelium. Subtypes of SIL were squamous, warty, basaloid, warty-basaloid, and papillary. Squamous hyperplasia, the most common lesion, was found in 83% of the cases, followed by LGSIL (59%) and HGSIL (44%). In 62% of the cases more than 1 associated lesion was present per specimen. A sequence from squamous hyperplasia to low-grade to high-grade SIL was seen frequently. Squamous hyperplasia was more commonly associated with usual squamous, papillary, and verrucous than with warty and basaloid invasive carcinomas. LGSIL was associated with all types of squamous cell carcinoma but was rarely present adjacent to basaloid or verrucous tumors. HGSIL was present in two thirds of invasive warty, basaloid, and mixed warty-basaloid tumors, in about half of usual squamous cell carcinomas, and was absent in papillary and verrucous carcinomas. Correlation of special types of invasive carcinomas with subtypes of SIL revealed morphologic correspondence of invasive tumor and the associated intraepithelial lesion. Squamous LGSIL was preferentially associated with verrucous, papillary, and usual squamous cell carcinomas; warty LGSIL, with invasive warty and mixed warty-basaloid carcinomas. High-grade SIL of the squamous type was frequently found in squamous cell carcinoma of usual type but was rarely present with warty or basaloid carcinomas. Basaloid HGSIL was associated with basaloid carcinoma, and HGSIL of warty type, with either warty or mixed warty-basaloid carcinomas. The high frequency of squamous hyperplasia and LGSIL and preferential association with usual, verrucous, and papillary carcinomas plus the subtle morphologic differences of the 2 lesions suggest that, despite its benign appearance, squamous hyperplasia is a precursor of the aforementioned carcinomas. The association and histologic similarities between high-grade SIL of the basaloid, warty, or mixed forms with their invasive counterparts indicate these lesions are their likely precursors.     

HPV infection in men

While much is known about the natural history of cervical human papillomavirus (HPV) infection and its consequences, including cervical intraepithelial neoplasia and cervical cancer, relatively little is known about the natural history of anogenital HPV infection and diseases in men. In part this reflects difficulties in penile sampling and visual assessment of penile lesions. Anal HPV infection and disease also remain poorly understood. Although HPV is transmitted sexually and infects the genitals of both sexes, the cervix remains biologically more vulnerable to malignant transformation than does the penis or anus in men. An understanding of male HPV infection is therefore important in terms of reducing transmission of HPV to women and improving women's health. However, it is also important due to the burden of disease in men, who may develop both penile and anal cancer, particularly among HIV-positive men who have sex with men. Improved sampling techniques of the male genitalia and cohort studies in progress should provide important information on the natural history of anogenital HPV infection and disease in men, including risk factors for HPV acquisition and transmission. The impact of HPV vaccination in women on male anogenital HPV infection will also need to be assessed.     

New pathologic entities in penile carcinomas: an update of the 2004 world health organization classification

Most primary malignant tumors of the penis are squamous cell carcinomas (SCC) of the usual type. In recent years several variants, each with distinctive clinicopathologic features, have been described. Pseudohyperplastic carcinoma and carcinoma cuniculatum are both low-grade, extremely well-differentiated SCC variants characterized by an indolent clinical course and good prognosis. The former, which may be confused with pseudoepitheliomatous hyperplasia, preferentially affects the inner foreskin mucosa of elderly men and the latter is a verruciform tumor with an endophytic, burrow-like pattern of growth. Pseudoglandular carcinoma (featuring solid tumor nests with extensive central acantholysis simulating glandular lumina) and clear cell carcinoma (human papillomavirus [HPV]-related tumors composed of periodic acid-Schiff positive clear cells) are aggressive tumors with a high incidence of inguinal nodal metastases. Papillary carcinomas are HPV-unrelated verruciform tumors composed of complex papillae with acanthosis, hyper- and parakeratosis, absence of koilocytes, irregular fibrovascular cores, and jagged tumor base. Finally, in warty-basaloid carcinomas areas of warty (condylomatous) and basaloid carcinomas coexist in the same tumor, either separated or intermingled, giving the tumor a variegated appearance. In this review special emphasis is given to the differential diagnosis of these special variants with a discussion of the possible implications for clinical management.     

Detection and typing of human papillomavirus DNA in penile carcinoma: evidence for multiple independent pathways of penile carcinogenesis

To clarify the role of human papillomavirus (HPV) in penile cancer we evaluated the prevalence of HPV DNA in different histological subtypes of penile carcinoma, dysplasia, and condyloma using a novel, sensitive SPF10 HPV polymerase chain reaction assay and a novel genotyping line probe assay, allowing simultaneous identification of 25 different HPV types. Formalin-fixed, paraffin-embedded tissue samples were collected from the United States and Paraguay. HPV DNA was detected in 42% cases of penile carcinoma, 90% cases of dysplasia, and 100% cases of condyloma. There were significant differences in HPV prevalence in different histological cancer subtypes. Although keratinizing squamous cell carcinoma and verrucous carcinoma were positive for HPV DNA in only 34.9 and 33.3% of cases, respectively, HPV DNA was detected in 80% of basaloid and 100% of warty tumor subtypes. There was no significant difference in HPV prevalence between cases from Paraguay and the United States. In conclusion, the overall prevalence of HPV DNA in penile carcinoma (42%) is lower than that in cervical carcinoma (approximately 100%) and similar to vulvar carcinoma (approximately 50%). In addition, specific histological subtypes of penile cancer--basaloid and warty--are consistently associated with HPV, however, only a subset of keratinizing and verrucous penile carcinomas is positive for HPV DNA, and thus these two tumor groups seem to develop along different pathogenetic pathways.     

p53 immunostaining in lichen sclerosus is related to ischaemic stress and is not a marker of differentiated vulvar intraepithelial neoplasia (d-VIN)

AIM: To analyse p53 immunoreactivity in 207 biopsy specimens of lichen sclerosus (LS) and "differentiated vulvar intraepithelial neoplasia" (d-VIN), a postulated precursor lesion for LS-associated vulvar squamous cell carcinoma (SCC), which is characterized by atypical basal keratinocyte proliferations with p53+ basal/suprabasal keratinocyte nuclei. METHODS AND RESULTS: Forty early, 78 classic, 30 hypertrophic vulvar LS, 26 paediatric vulvar and penile LS, 33 vulvar LS-associated SCC and 30 vulvar/penile control specimens were examined for p53 expression and the presence of d-VIN. Nuclear p53 staining was observed in 175/207 LS biopsy specimens. Eighty percent of early and 69% of paediatric LS showed discontinuous/continuous p53 staining in basal keratinocytes. Classic LS showed no p53 staining in 17%, discontinuous basal keratinocyte staining in 20%, continuous basal keratinocyte staining in 58%, basal/suprabasal staining in 5%. Hypertrophic LS revealed basal keratinocyte staining in 32% and basal/suprabasal staining in 61%. p53 staining was associated with sclerosis of blood vessels and dermis, lymphoid infiltrates, vasculitis and hypertrophic LS. d-VIN was seen in 2% of LS alone and in 24% of LS-associated SCC. CONCLUSION: d-VIN in LS is rare, while p53 staining is common and best explained as an ischaemic stress response due to poor oxygenation, vasculitis and inflammation rather than as a marker of a precancerous lesion in LS.     

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

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

HPV16 induces penile intraepithelial neoplasia and squamous cell carcinoma in transgenic mice: first mouse model for HPV-related penile cancer

Penile cancer is an under-studied disease that occurs more commonly in developing countries and 30–50% of cases show high-risk human papillomavirus (HPV) infection. Therapeutic advances are slow, largely due to the absence of animal models for translational research. Here, we report the first mouse model for HPV-related penile cancer. Ten-week-old mice expressing all the HPV16 early genes under control of the cytokeratin 14 (Krt14) gene promoter and matched wild-type controls were exposed topically to dimethylbenz(a)anthracene (DMBA) or vehicle for 16 weeks. At 30 weeks of age, mice were sacrificed for histological analysis. Expression of Ki67, cytokeratin 14, and of the HPV16 oncogenes E6 and E7 was confirmed using immunohistochemistry and quantitative PCR, respectively. HPV16-transgenic mice developed intraepithelial lesions including condylomas and penile intraepithelial neoplasia (PeIN). Lesions expressed cytokeratin 14 and the HPV16 oncogenes E6 and E7 and showed deregulated cell proliferation, demonstrated by Ki67-positive supra-basal cells. HPV16-transgenic mice exposed to DMBA showed increased PeIN incidence and squamous cell carcinoma. Malignant lesions showed varied histological features closely resembling those of HPV-associated human penile cancers. Wild-type mice showed no malignant or pre-malignant lesions even when exposed to DMBA. These observations provide the first experimental evidence to support the etiological role of HPV16 in penile carcinogenesis. Importantly, this is the first mouse model to recapitulate key steps of HPV-related penile carcinogenesis and to reproduce morphological and molecular features of human penile cancer, providing a unique in vivo tool for studying its biology and advancing basic and translational research. © 2020 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

Histologic classification of penile carcinoma and its relation to outcome in 61 patients with primary resection

A retrospective review of the clinical and pathologic features of 61 cases of penile squamous cell carcinoma (SCC), all treated by primary surgical resection at the Memorial Sloan Kettering Cancer Center during the period 1949-1992, was undertaken. Inguinal lymph node dissection material was evaluated in 40 cases. All carcinomas were of squamous cell type and were classified as follows: usual type, 36 cases (59%); papillary, not otherwise specified (NOS), 9 cases (15%), basaloid, 6 cases (10%); warty (condylomatous), 6 cases (10%); verrucous, 2 cases (3%), and sarcomatoid, 2 cases (3%). A high rate of nodal metastasis and poor survival were found for the basaloid and sarcomatoid neoplasms (5 of 7 patients with metastasis, 71%, and 5 of 8 dead of disease, 63%). Only 1 patient with a verruciform tumor (defined as a tumor of nonspecific papillary, warty, or verrucous type) had inguinal node metastasis and none died from penile cancer. An intermediate rate of metastasis and mortality (14 of 26, 54%, and 13 of 36, 36%, respectively) was found for typical SCC. Penile carcinomas are morphologically heterogeneous, and there is a correlation of histologic type and biologic behavior. This mandates accurate histologic subtyping by the pathologist.     

The retinoblastoma protein/p16 INK4A pathway but not p53 is disrupted by human papillomavirus in penile squamous cell carcinoma

Stankiewicz E, Prowse D M, Ktori E, Cuzick J, Ambroisine L, Zhang X, Kudahetti S, Watkin N, Corbishley C & Berney D M
(2011) Histopathology 58 , 433–439
The retinoblastoma protein/p16 ^INK4A pathway but not p53 is disrupted by human papillomavirus in penile squamous cell carcinoma Aims: The pathogenesis of penile squamous cell carcinoma (PSCC) is not well understood. Human papillomavirus (HPV) may be involved in carcinogenesis, but few studies have compared cell‐cycle protein expression in HPV positive and negative cancers. The aim was to determine the extent of HPV infection in different histological subtypes of PSCC and its impact on the expression of key cell‐cycle proteins: p53, p21, p16^INK4A and retinoblastoma (RB) protein. Methods and results: One hundred and forty‐eight PSCC samples were examined immunohistochemically for RB, p16^INK4A, p53 and p21 protein expression. One hundred and two cases were typed for HPV by PCR. HPV DNA was detected in 56% of tumours, with HPV16 present in 81%. Basaloid tumours were related strongly to HPV infection (10 of 13), while verrucous were not (three of 13). Fifty‐nine per cent (38 of 64) of usual type SCCs had HPV infection. RB protein correlated negatively (P < 0.0001) and p16^INK4A (P < 0.0001) and p21 (P = 0.0002) correlated positively with HPV infection. p53 did not correlate with HPV infection. Conclusions: HPV infection is present in more than half of penile cancers and it is responsible for RB pathway disruption. However, no link between HPV and p53 immunodetection was found. Only basaloid and half of usual‐type PSSCs correlate with HPV infection, confirming possible separate aetiologies for those tumours.     

宫颈鳞状细胞癌和癌前病变中Skp2表达及其与HPV16/18感染的关系

目的 探讨skp2在宫颈鳞状细胞癌和癌前病变中的表达规律及其与人乳头状瘤病毒(HPV)感染之间的关系.方法 采用免疫组织化学(ABC法)和原位杂交检测Skp2蛋白和HPV16/18 DNA在30例正常宫颈鳞状上皮、29例宫颈低级别上皮内瘤变、31例高级别上皮内瘤变和31例宫颈鳞状细胞癌中的表达.结果 Skp2在正常宫颈鳞状上皮中呈阴性,与宫颈低级别上皮内瘤变(阳性表达率为13.8%,4/29)之间差异无统计学意义(P>0.05).随着上皮病变级别升高,表达也逐渐增强,在宫颈鳞状细胞癌中表达更强;HPV16/18 DNA在四组中的阳性表达率,除高级别上皮内瘤变和宫颈鳞状细胞癌两组间差异无统计学意义外(均为96.8%),其余各组之间差异均有统计学意义(P<0.01);在宫颈低级别上皮内瘤变中skp2蛋白表达和HPV感染相关无统计学意义,但在高级别上皮内瘤变和宫颈鳞状细胞癌两组中均呈正相关(γ高级别=0.373,γ癌 =0.416,P<0.05).结论 Skp2过表达主要在宫颈鳞状细胞癌形成的中晚期起作用,可作为一个早期诊断恶性的指标,且可能与HPV16/18感染有协同作用.E7-skp2-Rb可能是HPV感染诱导宫颈鳞状细胞癌形成的一条新致癌途径.