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

Pathology of Squamous Cell Carcinoma of the Penis: Back to Square One

The landscape of squamous cell carcinoma of the penis (SCC-P) has undergone a significant transformation since the new World Health Organization classification of genitourinary cancers and recent European Association of Urology/American Association of Clinical Oncology guidelines. These changes emphasize the necessity to categorize SCC-P into 2 groups based on its association with human papillomavirus (HPV) infection. This shift has major implications, considering that prior knowledge was derived from a mix of both groups. Given the distinct prognosis, treatment options, and staging systems observed for HPV-associated tumors in other body areas, the question now arises: will similar patterns emerge for SCC-P?

Penile intraepithelial neoplasia incidence, clinical classification, microenvironment and implications for imiquimod treatment

OBJECTIVES

To provide an outline of the existing data on penile intraepithelial neoplasia (PeIN), as well as a narrative review on imiquimod (IQ; a toll-like receptor 7 agonist) treatment and immune microenvironment markers that may predict response to treatment.

METHODS

A narrative review of the literature from 2000 to the present was conducted on PubMed, and we describe the most relevant data and cross references.

RESULTS

The incidence of PeIN is increasing. Local therapy with IQ may offer an easy applicable treatment with complete response rates of up to 63% but can be associated with considerable side-effects. There is no conclusive data on the optimal treatment schedule for PeIN, but evaluation of treatment results for other human papillomavirus-related pre-malignancies suggest three times a week for a duration up to 16 weeks. There are no published studies concerning the PeIN immune microenvironment. However, findings from the few studies on penile cancer and pre-cancerous vulvar and cervical lesions imply that specific immune cell subpopulations can serve as future predictors for successful immunomodulation treatments such as IQ.

CONCLUSIONS

Overall, limited data are available on IQ treatment for PeIN and no published data exists on the PeIN immune microenvironment. Further translational studies are warranted to gain more understanding on the pathophysiology of PeIN and potential predictors of progression and of response to topical treatments.

WHO 2022 classification of penile and scrotal cancers: updates and evolution

Squamous cell carcinoma (SCC) is the most common malignant tumour of the penis. The 2022 WHO classification reinforces the 2016 classification and subclassifies precursor lesions and tumours into human papillomavirus (HPV)-associated and HPV-independent types. HPV-associated penile intraepithelial neoplasia (PeIN) is a precursor lesion of invasive HPV- associated SCC, whereas differentiated PeIN is a precursor lesion of HPV-independent SCC. Block-type positivity of p16 immunohistochemistry is the most practical daily utilised method to separate HPVassociated from HPVindependent penile SCC. If this is not feasible, the term SCC, not otherwise specified (NOS) is appropriate. Certain histologies that were previously classified as "subtypes" are now grouped, and coalesced as "patterns", under the rubric of usual type SCC and verrucous carcinoma (e.g. usual-type SCC includes pseudohyperplastic and acantholytic/pseudoglandular carcinoma, and carcinoma cuniculatum is included as a pattern of verrucous carcinoma). If there is an additional component of the usual type of invasive SCC (formerly termed hybrid histology), the tumour would be a mixed carcinoma (e.g. carcinoma cuniculatum or verrucous carcinoma with usual invasive SCC); in such cases, reporting of the relative percentages in mixed tumours may be useful. The consistent use of uniform nomenclature and reporting of percentages will inform the refinement of future reporting classification schemes and guidelines/recommendations. The classification of scrotal tumours is provided for the first time in the fifth edition of the WHO Blue book, and it follows the schema of penile cancer classification for both precursor lesions and the common SCC of the scrotum. Basal cell carcinoma of the scrotum may have a variable clinical course and finds a separate mention.

Penile Squamous Cell Carcinomas in Sub-Saharan Africa and Europe: Differential Etiopathogenesis

Penile squamous cell carcinomas (PSCC) are classified by the World Health Organization into two categories based on their relationship with the human papillomavirus (HPV): HPV-associated and HPV-independent. We compared a cohort of PSCC from Mozambique, a sub-Saharan country in southeast Africa with a high prevalence of HPV and HIV infection, and Spain, a country in southwestern Europe with a low prevalence of HPV and HIV, to study the distribution of the etiopathogenic categories of these tumors in both sites. A total of 79 PSCC were included in the study (28 from Mozambique and 51 from Spain). All cases underwent HPV-DNA polymerase chain reaction (PCR) testing, genotyping, and immunohistochemistry for p16 and p53. Any PSCC showing either p16 overexpression or HPV-DNA in PCR analysis was considered HPV-associated. Overall, 40/79 (50.6%) tumors were classified as HPV-associated and 39 (49.4%) as HPV-independent. The two sites showed marked differences: 25/28 (89.3%) tumors from Mozambique and only 15/51 (29.4%) from Spain were HPV-associated (p < 0.001). HPV16 was the most frequent HPV type identified in 64.0% (16/25) of the HPV-associated tumors from Mozambique, and 60.0% (9/15) from Spain (p = 0.8). On average, patients from Mozambique were almost two decades younger than those from Spain (mean age 50.9 ± 14.9 and 69.2 ± 13.3, respectively [p < 0.001]). In conclusion, significant etiopathogenic differences between PSCC in Mozambique and Spain were observed, with a remarkably high prevalence of HPV-associated tumors in Mozambique and a relatively low prevalence in Spain. These data may have important consequences for primary prevention of PSCC worldwide.

Disparities in Healthcare Access, Education, and Geographical Factors That Affect Surgical Outcomes in Penile Cancer

Objectives: To establish the level of access to healthcare, education, social and geographical factors predisposing a negative surgical outcome and higher mortality rate in patients with penile cancer.

Methods: This is a retrospective, longitudinal and analytical study. Ninety-three medical records of adult male patients diagnosed with penile cancer were reviewed. Fisher’s exact test was performed to determine the association between the level of healthcare, social and geographical factors, and the outcomes for penile cancer.

Results: Patients without primary care access had a higher chance of having lymphovascular invasion at the time of diagnosis (OR=37.5, P<0.0001), a higher mortality rate at 24 months after diagnosis (OR=19.2, P=0.005), a lack of high school diploma or equivalent (OR=3.8, P=0.049) and a higher likelihood of referral from a provincial hospital (OR=10.1, P<0.0001). Patients without a favorable surgical outcome (radical penectomy) were more likely to have been referred from a provincial hospital (OR=6.8, P<0.0001) and not have access to a primary care center (OR=149.5, P<0.0001), a tertiary care center (OR=20.7, P=0.003), and a high school diploma (OR=7.9, P=0.004). 

Conclusions: The lack of access to primary care is strongly associated with vascular invasion at diagnosis, lower educational level, a referral from provincial zones, and a higher mortality rate at 24 months. Patients who did not have access to primary and tertiary care, a high school diploma, and were referred from the province were more likely to have a radical penectomy.

Pathological characterization and clinical outcome of penile intraepithelial neoplasia variants: a North American series

Penile intraepithelial neoplasia (PeIN) is classified as human papillomavirus (HPV)- and non-HPV-related. This classification is associated with distinct morphologic subtypes. The natural history and prognosis of PeIN subtypes are not well known. This study aims to evaluate clinicopathological features, HPV status, and outcome of PeIN subtypes. Eighty-two lesions from 64 patients with isolated PeIN were retrospectively reviewed. Mean age was 59 years. Lesions were multicentric in 34% of patients and affected glans (33%), shaft (26%), and foreskin (20%). Histologically, 22% of patients had coexisting lesions, classified as hybrid and mixed. HPV-related PeIN (97%) included basaloid (59%), warty (8%), warty-basaloid (8%), hybrid (19%) and mixed (3%) types. P16 and HPV positivity occurred in 99% and 82% of lesions, respectively. HPV 16 was more common in basaloid PeIN. Multiple genotypes were detected in 35%, more commonly in hybrid PeIN (P = 0.051). Positive margins occurred in 63% of excisions. PeIN recurred in 48% of excisions and 30% of overall repeated procedures, and progression to invasive carcinoma occurred in 2%. At follow-up, 86% of patients had no evidence of disease and 12% were alive with disease. Lichen sclerosus occurred in non-HPV and HPV-related PeIN (100% and 47%).In conclusion, HPV-related and, more specifically basaloid PeIN were the predominant types and preferentially associated with HPV 16. While PeIN had a high recurrence rate, there was a slow and infrequent progression to invasive or metastatic carcinoma with multimodal treatments. Additional studies are needed to understand biology and natural history of PeIN.

HPV-negative Penile Intraepithelial Neoplasia (PeIN) With Basaloid Features

Most human papillomavirus (HPV)-independent penile squamous cell carcinomas (PSCCs) originate from an intraepithelial precursor called differentiated penile intraepithelial neoplasia, characterized by atypia limited to the basal layer with marked superficial maturation. Previous studies in vulvar cancer, which has a similar dual etiopathogenesis, have shown that about one fifth of HPV-independent precursors are morphologically indistinguishable from high-grade squamous intraepithelial lesions (HSILs), the precursor of HPV-asssociated carcinomas. However, such lesions have not been described in PSCC. From 2000 to 2021, 55 surgical specimens of PSCC were identified. In all cases, thorough morphologic evaluation, HPV DNA detection, and p16, p53, and Ki-67 immunohistochemical (IHC) staining was performed. HPV-independent status was assigned based on both negative results for p16 IHC and HPV DNA. Thirty-six of the 55 PSCC (65%) were HPV-independent. An intraepithelial precursor was identified in 26/36 cases (72%). Five of them (19%) had basaloid features, morphologically indistinguishable from HPV-associated HSIL. The median age of the 5 patients was 74 years (range: 67 to 83 y). All 5 cases were p16 and DNA HPV-negative. Immunohistochemically, 3 cases showed an abnormal p53 pattern, and 2 showed wild-type p53 staining. The associated invasive carcinoma was basaloid in 4 cases and the usual (keratinizing) type in 1. In conclusion, a small proportion of HPV-independent PSCC may arise on adjacent intraepithelial lesions morphologically identical to HPV-associated HSIL. This unusual histologic pattern has not been previously characterized in detail in PSCC. p16 IHC is a valuable tool to identify these lesions and differentiate them from HPV-associated HSIL.

[The malignant epithelial carcinomas of the penis: A review of the different histological types]

The most frequent cancer of the penis is the squamous cell carcinoma. Several variants of squamous cell carcinoma exist. It is important to make a difference between squamous cell carcinomas with and without a HPV infection. Furthermore, it is extremely important to recognize the different variants as their prognosis differs. These tumors are rare therefore classifying them can be challenging. This review is supposed to give an overview on the existing entities since 2016, but also allows a glimpse into the future with some comments on the upcoming WHO classification 2021.

[Penile intraepithelial neoplasia]

Penile carcinogenesis can be superposed on vulvar carcinogenesis, with two pathways : with or without a link to HPV. Penile squamous cell carcinomas arise from precursor lesions: penile intraepithelial neoplasia (PeIN) defined by the presence of intraepithelial atypia, which can progress to invasive squamous cell carcinoma. Differentiated PeINs not linked to HPV, affect elderly men with inflammatory lesions, most often lichen sclerosus. PeINs linked to HPV, basaloid, condylomatous or condylomatous-basaloid growth affect younger men. Although clinically similar, their distinction is important, because the treatment differs with a greater risk of invasion for forms unrelated to HPV.

[Non-invasive precursor lesions of penile carcinoma : Differential diagnosis and treatment]

Clinical diagnosis of preinvasive malignant lesions of the penis is difficult and there are numerous differential diagnoses. Recent decades have been witness to several changes in the terminology of histopathological diagnoses. In the current World Health Organization classification, penile intraepithelial neoplasia (PeIN) is defined, of which several subtypes exist. Just like in invasive carcinoma, the principal classification of PeIN subtypes corresponds with pathogenesis and includes human papilloma virus (HPV)-related and non-HPV-related forms. Subdivision is important for prognosis. Several therapeutic options exist, including surgical and nonsurgical procedures.

[Penile carcinoma: Practical issues, from the biopsy to surgery]

The management of a penile carcinoma is complex, a collaboration between radiologist, pathologist and urologist is necessary to obtain a correct staging. In this review we try to demonstrate step by step how to achieve a complete pathology report, how to manage the patient (imaging, biopsy, fresh frozen section and surgery).

The prevalence of human leucocyte antigen and human papillomavirus DNA in penile intraepithelial neoplasia in England 2011-2012

BACKGROUND

The pathogenesis of penile intraepithelial neoplasia (PeIN) is unclear but human papillomavirus (HPV) infection and polymorphisms in human leucocyte antigen (HLA).

OBJECTIVES

To examine the prevalence of HPV DNA and HLA in PeIN.

METHODS

Adult Caucasian men with a clinical and histological diagnosis of PeIN, that is, Bowenoid papulosis (BP), Bowen's disease of penis (BDP) and erythroplasia of Queyrat (EQ) were selected and phenotyped from the clinical records. DNA was extracted from blood and paraffin-embedded sections for HLA and HPV typing, respectively. Human leucocyte antigen allele frequencies were compared with those derived from the UK-based Caucasian population.

RESULTS

Seventy-two cases of PeIN (20 BP, 34 BDP and 18 EQ) were studied. Human papillomavirus DNA was identified in 65/72 (90.2%) PeIN; Alphapapillomavirus types were detected in 62/72 (85%) followed by Betapapillomavirus types in 9/72 (12.5%) and cutaneous types in 7/72 (9.7%); HPV16 was the most prevalent genotype at 35/72 (48.6%) followed by HPV33 at 7/72 (9.7%); multiple infections were seen in 18/72 (25%) PeIN. HLA-C*15 (Bonferroni corrected p = 0.049) confers susceptibility to PeIN, whereas HLA-DQA1*01 (corrected p = 0.02) protects against PeIN. HPV16-associated PeIN cases showed no statistically significant association with HLA genotype after multiple corrections.

CONCLUSION

Human papillomavirus is involved in the pathogenesis of PeIN. Immunogenotype may play a role in the pathogenesis of PeIN.

Balanopreputial sac and urine microbiota in patients with male genital lichen sclerosus

BACKGROUND

Male genital lichen sclerosus (MGLSc) is a chronic inflammatory scarring dermatosis associated with penile carcinoma. The prepuce is pivotal in its etiology. Other proposed etiological factors are the subject of dispute and include occluded urinary exposure, autoimmunity, immunodysregulation, and infectious agents.

OBJECTIVE

To determine whether the bacterial microbiota of the balanopreputial sac and urine are associated with MGLSc.

SUBJECTS AND METHODS

Twenty uncircumcised patients with MGLSc and 20 healthy uncircumcised males were enrolled in a prospective case-control study. Balanopreputial swabs and urine specimens were subjected to 16S rRNA gene amplicon sequencing.

RESULTS

Microbiota analysis indicated differences between the groups. In the balanopreputial sac, the median relative abundance of Finegoldia spp. was lower (9% [range 0-60%]) in MGLSc patients than in controls (28% [range 0-62%]). Conversely, the median relative abundance of Fusobacterium spp. was higher in MGLSc patients (4% [range 0-41%]) than in controls (0% [range 0-28%]). In the urine, the median relative abundance of Finegoldia spp. was comparable between groups, whereas that of Fusobacterium spp. was higher in MGLSc patients (0% [range 0-18%] vs. 0% [range 0-5%]). There was a strong association between the microbiota composition of the balanopreputial sac and urine in MGLSc.

CONCLUSION

Dysbiosis could be involved in the etiopathogenesis of MGLSc. Further studies are required to confirm the association suggested herein and to determine its nature.

Evolving insights into penile cancer pathology and the eighth edition of the AJCC TNM staging system

The majority of penile malignant tumors are squamous cell carcinomas. They are pathologically defined as epithelial neoplasms originating in the squamous cells of the inner mucosal lining of the glans, coronal sulcus or foreskin. Tumor location and site of origin is preferentially in glans (70%) followed by foreskin (25%) and coronal sulcus (5%). Despite the variable geographic distribution, pathological features of penile carcinomas in areas of high- and low-risk are similar. Penile tumors are morphologically heterogeneous. A major advance, based on biological, etiological and prognostic factors, is the 2016 WHO classification separating epithelial penile neoplasia, precancerous and invasive, in non-HPV and HPV-related.

Paving the way for more precise diagnosis of EcPV2-associated equine penile lesions

Background

There is growing evidence that equine papillomavirus type 2 (EcPV2) infection is causally associated with the development of equine genital squamous cell carcinomas (SCCs). Early stages of disease present clinically as plaques or wart-like lesions which can gradually progress to tumoural lesions. Histologically these lesions are inconsistently described as benign hyperplasia, papilloma, penile intraepithelial neoplasia (PIN), carcinoma in situ (CIS) or SCC. Guidelines for histological classification of early SCC precursor lesions are not precisely defined, leading to potential misdiagnosis. The aim of this study was to identify histologic criteria and diagnostic markers allowing for a more accurate diagnosis of EcPV2-associated equine penile lesions.

Results

A total of 61 archived equine penile lesions were histologically re-assessed and classified as benign hyperplasia, papilloma, CIS or SCC. From these, 19 representative lesions and adjacent normal skin were comparatively analysed for the presence of EcPV2 DNA and transcripts using PCR and RNA in situ hybridisation (RISH). All lesional samples were positive by EcPV2 PCR and RISH, while adjacent normal skin was negative. RISH analysis yielded signal distribution patterns that allowed distinction of early (hyperplasia, papilloma) from late stage lesions (CIS, SCC). Subsequently, the 19 lesions were further assessed for expression of p53, Ki67, MCM7 and MMP1 by immunohistochemistry (IHC). All four proteins were expressed in both normal and lesional tissue. However, p53 expression was up-regulated in basal keratinocyte layers of papillomas, CIS and SCCs, as well as in upper keratinocyte layers of CIS and SCCs. MCM7 expression was only up-regulated in upper proliferating keratinocyte layers of papillomas, CIS and SCCs.

Conclusion

This study proposes combining a refined histological protocol for analysis of equine penile lesions with PCR- and/or RISH based EcPV2-screening and p53/MCM7 IHC to more accurately determine the type of lesion. This may help to guide the choice of optimum treatment strategy, especially at early stages of disease.

Laryngeal Squamous Cell Carcinomas are Commonly Associated With Differentiated Squamous Intraepithelial Neoplasia With or Without an Admixture With Usual Type of Squamous Intraepithelial Neoplasia: Clinical and Pathologic Significance

BACKGROUND

Differentiated squamous intraepithelial neoplasia (dSIN) is a pathway in the development of invasive squamous cell carcinoma (SCC) distinct from the usual-type squamous intraepithelial neoplasia (uSIN) and has not been described in the larynx.

MATERIALS AND METHODS

Sixty-nine consecutive cases of SCC were identified which included 25 dSIN, 13 uSIN, and 31 mixed dSIN+usual-like SIN (u-like SIN) cases.

RESULTS

dSIN was characterized by atypical squamous cells limited to the basal/parabasal layers and u-like SIN was characterized by cytologic atypia limited to less than full thickness. Despite the lack of neoplastic involvement of the full thickness of the epithelium, these types of SIN were commonly connected with invasive carcinoma. Prior biopsies demonstrating only dSIN, without the underlying invasive SCC, were underdiagnosed in 2 cases. Because of the frequent keratinization, u-like SIN likely represents the "keratinized dysplasia" and shows changes suggestive of dSIN with upward spread of neoplastic cells into the upper layer of the epithelium.

CONCLUSIONS

Laryngeal dSIN represents an important but under recognized pathway of invasive SCC development. As moderate dysplasia of uSIN type are not associated with invasive SCC, labeling u-like SIN as dysplasia of grade 2 or 3 likely leads to the controversies in the current grading systems in the upper aerodigestive system and causes confusion for clinicians.

Premalignant male genital dermatoses

The spectrum of conditions affecting the penile skin is varied and ranges from simple, benign dermatoses to premalignant and malignant conditions. Anogenital malignancies and premalignancies are an important personal/public health problem due to their effects on individuals' physical, mental, and sexual health. Furthermore, due to their etiological association with human papillomavirus infection, anogenital malignancies, and premalignancies constitute an immense public health burden. Bowen's disease, Bowenoid papulosis, and erythroplasia of Queyrat are the most widely seen premalignancies of anogenital region and are all forms of squamous intraepithelial neoplasia. Histopathologically, these conditions share identical histologic features of squamous cell carcinoma in situ, but their clinical features differ. In this article, we explore the common precancerous states that can lead to penile carcinoma.

Verruciform and Condyloma-like Squamous Proliferations in the Anogenital Region

CONTEXT.—

Histologic distinction between condyloma acuminatum and various benign and malignant condyloma-like lesions in the anogenital area poses a common diagnostic challenge to pathologists across subspecialties.

OBJECTIVE.—

To review the overlapping and distinguishing features of condyloma acuminatum and its mimics, and to clarify confusing terminology and diagnostic criteria for problematic entities.

DATA SOURCES.—

A review of the literature on condyloma acuminatum (ordinary and giant types), verrucous carcinoma, warty/warty-basaloid high-grade squamous intraepithelial lesion and squamous cell carcinoma, papillary squamous cell carcinoma, bowenoid papulosis, verruca vulgaris, epidermolytic acanthoma, and verruciform xanthoma was performed.

CONCLUSIONS.—

Correct diagnosis of condyloma acuminatum and condyloma-like lesions has important clinical implication and entails familiarization with their clinical presentations and histopathologic features. Contrary to historical belief, giant condyloma acuminatum and verrucous carcinoma should be considered distinct entities based on different pathogenetic pathways. Ancillary tools available for identifying and genotyping human papillomavirus can aid in diagnosis when histopathologic findings are inconclusive. Recognition of relatively rare entities such as bowenoid papulosis, epidermolytic acanthoma, and verruciform xanthoma would avoid overdiagnosis and unnecessary, overaggressive treatment.

[Penile intra-epithelial neoplasia]

INTRODUCTION

Penile intra-epithelial neoplasia (PIN) are precancerous lesions, characterized by architectural and cytological abnormalities of the genital epithelium, from which can arise squamous carcinomas.

METHODS

A literature review was performed on the Medline database, considering the articles listed between October 2007 and October 2017 dealing with PIN, using the following keywords "intraepithelial neoplasia" or "Bowen's disease" or "erythroplasia of Queyrat" or "bowenoid papulosis" and "penis ». Papers were selected according to their language (English and French) and their relevance.

RESULTS

One hundred seventy four articles related to PIN were listed. Twenty-five of them were selected for their relevance. The analysis of the references of these articles identified 6 relevant papers published before October 2007, which were considered for this review based on a total of thirty-one articles. We describe clinical and pathological characteristics of PIN, emphasizing treatment modalities.

CONCLUSION

Urologists should distinguish HPV-related and non HPV-related PIN, both of them sharing clinical presentation, but needing different management.

Papillomavirus infection and squamous cell carcinoma in horses

Squamous cell carcinoma (SCC) is a common disease that seriously impairs the health and welfare of affected horses and other equids. In humans, almost all cervical carcinomas, a high percentage of anogenital SCCs and a subset of SCCs of the head and neck are caused by high-risk human papillomavirus (hrHPV) infection. Since hrHPV-induced human cancers and equine SCC have similar cytological and histopathological features, it has been hypothesised that equine SCCs could also be induced by papillomaviruses. This review provides an overview of the current evidence for an aetiological association between papillomavirus infections and equine SCCs and SCC precursor lesions. SCC of apparently papillomavirus-unrelated aetiology are also discussed, as are recent advances in equine SCC prophylaxis.

Review of in situ and invasive penile squamous cell carcinoma and associated non-neoplastic dermatological conditions

Penile carcinoma is a rare genitourinary malignancy in North America and Europe with highest rates recorded in South America, Africa and Asia. Recent classifications have refined the terminology used in classifying intraepithelial/in situ lesions and additionally newer entities have been recognised in the invasive category. While increasing recognition of a bimodal pathway of penile carcinogenesis has facilitated understanding and classification of these tumours, handling and subtyping of penile malignancies presents a challenge to the reporting pathologist, in part due to their rarity. This article reviews the terminology and classification of in situ and invasive carcinomas and their relationship to human papilloma virus status. In addition, associated non-neoplastic dermatological conditions of relevance and appropriate ancillary investigations will be addressed.

The role of histologic subtype, p16(INK4a) expression, and presence of human papillomavirus DNA in penile squamous cell carcinoma

Background

Up to 50% of penile squamous cell carcinomas (pSCC) develop in the context of high-risk human papillomavirus (HR-HPV) infection. Most of these tumours have been reported to show basaloid differentiation and overexpression of tumour suppressor protein p16^INK4a. Whether HPV-triggered carcinogenesis in pSCC has an impact on tumour aggressiveness, however, is still subject to research.

Methods

In tissue specimens from 58 patients with surgically treated pSCC between 1995 and 2012, we performed p16^INK4a immunohistochemistry and DNA extraction followed by HPV subtyping using a PCR-based approach. The results were correlated with histopathological and clinical parameters.

Results

90.4% of tumours were of conventional (keratinizing) subtype. HR-HPV DNA was detected in 29.3%, and a variety of p16^INK4a staining patterns was observed in 58.6% of samples regardless of histologic subtype. Sensitivity of basaloid subtype to predict HR-HPV positivity was poor (11.8%). In contrast, sensitivity and specificity of p16^INK4a staining to predict presence of HR-HPV DNA was 100% and 57%, respectively. By focussing on those samples with intense nuclear staining pattern for p16^INK4a, specificity could be improved to 83%. Both expression of p16^INK4a and presence of HR-HPV DNA, but not histologic grade, were inversely associated with pSCC tumour invasion (p = 0.01, p = 0.03, and p = 0.71). However, none of these correlated with nodal involvement or distant metastasis. In contrast to pathological tumour stage, the HR-HPV status, histologic grade, and p16^INK4a positivity failed to predict cancer-specific survival.

Conclusions

Our results confirm intense nuclear positivity for p16^INK4a, rather than histologic subtype, as a good predictor for presence of HR-HPV DNA in pSCC. HR-HPV / p16^INK4a positivity, independent of histological tumour grade, indicates a less aggressive local behaviour; however, its value as an independent prognostic indicator remains to be determined. Since local invasion can be judged without p16^INK4a/HPV-detection on microscopic evaluation, our study argues against routine testing in the setting of pSCC.

Glans resurfacing for precancerous and superficially invasive carcinomas of the glans penis: Pathological specimen handling and reporting

Glans resurfacing is a recently described technique in the management of precancerous lesions and superficial invasive tumours of the glans penis as well as cases of indolent persistent lichen sclerosus. The technique is complex and is usually only practiced in specialist centres with combined urological and plastic surgical expertise. Cosmetic and functional results are better than in more extensive penile surgery, such as glansectomy, for such cases, cancer cure and control is comparable. Knowledge of the technique used and the spectrum of disease are vital for appropriate specimen handling and pathological reporting of these complex cases to aid further management and avoid over reporting of positive margins.

Clinicopathological features of carcinoma of the distal penile urethra

Distal urethral carcinomas are very rare and are similar in their pathology and behaviour to tumours of the glans penis and foreskin. Similarly they are associated with penile intraepithelial neoplasia (PeIN) of both differentiated and undifferentiated types. Current management is mainly surgical, but increasingly involves specialist penile-preserving techniques. Handling and dissection of the specimens is broadly the same as other primary penile tumours. The prognosis of distal urethral lesions is believed to be worse than penile tumours and better than prostatic urethral tumours, but the evidence is sparse. The staging system for urethral tumours does not distinguish between proximal and distal, apart from prostatic urethra, and has led to much confusion in the literature. Although the subtypes of tumours seen in the distal urethra are the same as those on the glans and foreskin, there is an increased proportion of basaloid squamous carcinoma and malignant melanoma whereas the majority of tumours seen in the proximal and prostatic urethra are of urothelial origin. In future, distal urethral tumours should be separately designated with site-specific staging/TNM and reporting system and pathologically classified in the same way as penile and foreskin tumours. Ultimately, this will improve the quality of data and produce evidence to inform management.

Histologic and immunohistochemical assessment of penile carcinomas in a North American population

Penile squamous cell carcinoma (SCC) is sometimes an aggressive disease that has a variable worldwide incidence, in part due to differing rates of inflammatory and infectious risk factors. In the developed world, penile SCC is a rare malignancy, and most studies therefore originate in less developed countries. The current study was undertaken to examine the morphologic and immunohistochemical features of penile SCC from a region with low disease incidence. Sixty-two complete or partial penectomy specimens from 59 patients were reviewed. Twenty-six patients had metastasis, 3 had recurrent disease, and 7 were dead due to tumor. Most patients were uncircumcised (72%). Twenty-two percent of carcinomas were associated with lichen sclerosis. Perineural invasion was significantly associated with metastasis (P=0.007). Most SCCs (65%) had the usual keratinizing morphology, and these tumors were significantly associated with the differentiated form of intraepithelial lesion (P<0.0001), p53 positivity (P=0.002), cyclin D1 positivity (P=0.007), and EGFR overexpression (P=0.003). Human papilloma virus (HPV)-associated tumors accounted for 27% and were basaloid (8%), warty (10%), mixed (6%), or lymphoepithelioma-like carcinoma (4%) variants. These were significantly associated with p16 expression (P<0.0001) and the undifferentiated form of intraepithelial lesion (P<0.001). Among all SCCs, there was no difference in the immunohistochemical or in situ hybridization profile between primary tumors and metastases. Although penile SCC is rare in the United States, the tumor variants, immunohistochemical profiles, and proportion of HPV-associated tumors are similar to those in less developed countries. Two distinct pathways appear to lead to carcinogenesis; one is related to underlying chronic inflammatory states, involves p53 mutation, cyclin D1 overexpression, and culminates in classic keratinizing SCC. The other pathway involves high-risk HPV infection, demonstrates strong p16 expression, and results in SCC with varied, but distinctive morphologies.

Histopathogenesis of non-HPV-related differentiated oral squamous intraepithelial neoplasia

INTRODUCTION

A study of immunohistopathologic and cytohistopathologic changes of the parabasal/basal layers in the differentiated squamous intraepithelial neoplasia (DSIN) may elucidate the histopathogenesis and reveal changes aiding early diagnosis and grading of the lesion.

MATERIALS AND METHODS

A total of 55 consecutive resection specimens of nonbasaloid squamous cell carcinoma of the anterior oral cavity and 8 biopsies before resections displaying DSIN in the overlying squamous epithelium were examined.

RESULTS

Squamous epithelium that is continuous/immediately adjacent to invasive squamous cell carcinoma (type 1) and the more peripheral (type 2) epithelium of resection specimens displayed consistent changes in the parabasal/basal layers: (A) cytologic atypia with proliferation of parabasal cells with downward expansion causing reactive proliferation of the basal cell layer in the early stage, invading the basal layer in the late stage; (B) disordered nuclear/cytoplasmic arrangement; (C) "Cobblestone" appearance. Immunoreactivity for TP53 and Ki67 was helpful in the diagnosis. The epithelial spectrum of changes decreased as one moved from type 1 to type 2 lesions. Five out of 8 biopsies showed type 1 lesions (followed by resection in a period of 11±6 mo) and 3 showed type 2 lesions (followed by resection in a period of 55±20 mo). In addition, resections were margin positive for type 2 lesions in 5 cases associated with recurrence at the site of resection during a period of 69±9 months.

CONCLUSIONS

DSIN is characterized by a proliferation of neoplastic parabasal cells with dyskeratosis, downward expansion/pushing of the basal layer with elongation of rete ridges. We proposed grading of DSIN based on the changes of the parabasal/basal layers.

Squamous Cell Carcinomas of the Anterior Oral Cavity Are Commonly Associated With Simplex (or Differentiated) Oral Intraepithelial Neoplasia

Introduction: We investigated the occurrence of differentiated oral intraepithelial neoplasia (DOIN) that met the criteria for differentiated intravulvar neoplasia, associated with invasive squamous cell carcinoma (SCC) of the anterior oral cavity, and its clinicopathologic significance. Materials and Methods: Sixty-nine consecutive cases of SCC of the anterior oral cavity were categorized into 2 groups: group A comprised SCC associated with DOIN; Group B consisted of cases associated with classical SCC in situ. Results: Fifty-five cases (80%) were classified as group A, or DOIN lesions, with only 14 (20%) as group B. All cases were associated with invasive SCC, except 2 cases in group B. Squamous epithelium continuous or adjacent to invasive SCC displayed consistent changes in the parabasal and basal layers with (1) cytologic atypia with proliferation of parabasal cells in downward expansion causing reactive proliferation of the basal cell layer in early stage and invading the basal layer in late stage, (2) disordered nuclear/cytoplasmic arrangement, and (3) a “cobblestone” appearance characterized by prominent intercellular spaces and cytoplasmic density involving the entire cell (dyskeratosis) of the parabasal layer. p53 and Ki67 immunostaining revealed linear reactivity mainly in the parabasal layer. Conclusions: DOIN lesions are frequently associated with invasive SCC of anterior oral cavity. Due to the subtle histopathologic changes, DOIN lesions pose potential diagnostic difficulty with differentiation from mild dysplasia or reactive atypia.

Does the width of the surgical margin of safety or premalignant dermatoses at the negative surgical margin affect outcome in surgically treated penile cancer?

AIMS

To evaluate the prognostic impact of the width of negative surgical margins (NSM) and associated and preinvasive lesions at the NSM in patients with penile squamous cell cancer (PSC).

METHODS

Enrolling 87 patients with NSM who underwent surgery for PSC, the archived margin slides and entirely wax-embedded surgical margins were retrieved from the pathology files. After step sections were cut, margins were stained with antibodies against CK5/6, p16, p53 and Ki-67 and subjected to in situ hybridisation for high-risk human papillomavirus (HPV). All NSM were histologically examined for squamous hyperplasia (SH), lichen sclerosus (LS) and subtypes of penile intraepithelial neoplasia (PeIN). Then, histological findings were correlated with cancer-specific mortality (CSM, median follow-up 34 months; IQR 6-70).

RESULTS

All NSM were negative for high-risk HPV and exhibited SH (p16 and p53 negative, Ki-67 variably positive), LS (p16 negative, variable p53 and Ki-67 positivity) and differentiated PeIN (dPeIN; p16 negative, Ki-67 positive, variable p53 positivity) in 28 (32%), 30 (34%) and 22 (25%) cases, respectively, whereas PeIN subtypes other then dPeIN did not occur. Pathological tumour stage was the only independent predictive parameter with respect to CSM in the multivariable analysis (p=0.001).

CONCLUSIONS

SH, LS and dPeIN are frequent histological findings at the NSM of surgically treated PSC. However, neither the width of the NSM nor dPeIN, LS or SH at the NSM influences prognostic outcome.

Differentiated dysplasia is a frequent precursor or associated lesion in invasive squamous cell carcinoma of the oral cavity and pharynx

The source of precursor lesions of squamous cell carcinoma (SCC) of the oral cavity and pharynx, their classification, and grading are controversial. In contrast, vulvar and penile cancer precursor lesions are known to be related to human papillomavirus or chronic inflammation and can be described using the vulvar intraepithelial neoplasia (VIN) classification system (VIN 1-3) or as differentiated vulvar intraepithelial neoplasia (dVIN), respectively. Oral and pharyngeal SCC precursor lesions are more etiologically diverse, and the spectrum of lesions may thus be wider. No international consensus exists regarding the histological types of precursor lesions or the significance of individual types. We therefore reviewed resection specimens and preceding biopsies of 155 patients with SCC of the oral cavity and pharynx (excluding tonsils) and identified five basic patterns of SCC-associated or precursor lesions: (1) pleomorphic (22/155), (2) basaloid (5/155), (3) differentiated (63/155), (4) mixed (42/155), and (5) verrucous (12/155). Keratinization was a common but variable feature in differentiated, mixed, and verrucous dysplasia. In 11/155 patients, no precursor lesion could be identified. Progression of isolated differentiated dysplasia (ranging from months to years) was documented in 13/155 (8 %) of patients. Our data suggest that full-thickness epithelial dysplasia of pleomorphic or basaloid type is present in <20 % of oral and pharyngeal SCC, and differentiated dysplasia is a frequent precursor or associated in situ lesion. Failure to recognize differentiated dysplasia results in the underdiagnosis of many patients at risk for invasive carcinoma. These results indicate a need to refine criteria to distinguish differentiated dysplasia from morphologically related lichenoid lesions.

Male genital premalignant dermatoses

The spectrum of conditions affecting the penile skin is varied and ranges from simple, benign dermatoses to premalignant and malignant conditions. Recently, improved understanding of the aetiology and natural history of these conditions has shaped new treatment paradigms and a functional knowledge of dermatology, urology and genitourinary medicine is required to successfully diagnose and treat these men. In this article, we explore the common precancerous states that can lead to penile carcinoma and review the recent advances with regards to the molecular basis for these dermatoses and the treatments that may be most effective for these men.

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.