Distinctive Association of p16INK4a Overexpression With Penile Intraepithelial Neoplasia Depicting Warty and/or Basaloid Features: A Study of 141 Cases Evaluating a New Nomenclature

Current update on pharmacological strategies of penile cancer

INTRODUCTION

Penile cancer considered an orphan malignancy - due to its low incidence - makes research and clinical development challenging. The limited understanding of molecular biology and genetic landscape adds to the complexity of developing effective therapies.

AREAS COVERED

This review takes a closer look at how penile cancer treatment has evolved - from traditional modes like surgery and radiation to now vaccines - over the period of time. Breakthroughs in immunotherapy offer a ray of hope alongside treatments like adoptive T-cell therapies (ATCT), anti-angiogenic agents, Antibody-Drug Conjugates (ADCs), and Bispecific Antibodies (BsAbs).

EXPERT OPINION

The integration of immunotherapy and targeted therapy has demonstrated promising results, particularly in patients with advanced or metastatic disease. While these advancements bring hope, more research is needed to refine treatment strategies to benefit patients from these novel approaches.

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.

Squamous Cell Carcinoma In Situ-The Importance of Early Diagnosis in Bowen Disease, Vulvar Intraepithelial Neoplasia, Penile Intraepithelial Neoplasia, and Erythroplasia of Queyrat

Cutaneous squamous cell carcinoma (cSCC) is the second-most-prevalent malignancy in humans. A delayed diagnosis of cSCC leads to heightened invasiveness and positive surgical margins. Bowen's disease (BD) represents an early form of cSCC and presents as a small erythematous, photo-distributed, psoriasiform plaque. Although certain dermoscopy features in BD are quite characteristic, histopathology remains the gold standard for diagnosis and provides a severity-scoring system that assists in guiding appropriate treatment strategies. The classification of precancerous lesions of the vulva and penis has undergone multifarious transformations due to variations in clinical and histopathological characteristics. Presently, erythroplasia of Queyrat is categorized as a clinical variant of penile intraepithelial neoplasia (PeIN). The diagnoses of vulvar intraepithelial neoplasia (VIN) and PeIN present significant challenges and typically necessitate one or more biopsies, potentially guided by dermoscopy. Aceto-white testing demonstrates a notably high negative predictive value for genital precancerous lesions. Histopathological examination represents the gold-standard diagnosis in VIN and PeIN, while p16 and p53 immunostainings alongside HPV testing provide crucial diagnostic clues. The histopathologic features, degree of differentiation, and associations with lichen planus, lichen sclerosus, and HPV guide the selection of conservative treatments or surgical excision.

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?

The Spectrum of HPV-independent Penile Intraepithelial Neoplasia: A Proposal for Subclassification

Compared with vulva, precursor lesions of human papillomavirus (HPV)-independent invasive squamous cell carcinoma (SCC) of the penis are insufficiently characterized. We analyzed the histologic and immunohistochemical characteristics of 70 peritumoral precursor lesions and correlated them with the histology and mutational profile of the adjacent HPV-negative invasive penile SCC. Atypical basal keratinocyte proliferation with variously elongated epithelial rete with premature squamatiziation, but regular superficial cornification, termed differentiated penile intraepithelial neoplasia (d-PeIN), were identified adjacent to 42/70 (60%) SCC (36/42 keratinizing ( P <0.001); 3 papillary, and 1 each verrucous, clear cell, sarcomatoid SCC). d-PeIN were associated with chronic inflammatory dermatoses (32/42; P <0.001), p53 overexpression (26/42; P <0.001), and hotspot mutations in TP53 (32/42; P <0.001), CDKN2A (26/42; P <0.001) or both (21/42; P =0.003) in the adjacent SCC. Cytoplasmic p16 ink4a overexpression in 5/42 d-PeIN correlated with CDKN2A missense mutations in the adjacent SCC. In all, 21/70 (30%) cornified verrucous or glycogenated verruciform precursors with minimal atypia and wild-type p53 (18/21; P <0.001) occurred adjacent to verrucous or papillary SCC (17/21; P <0.001) and keratinizing (4/21) SCC, which harbored mutations in HRAS and/or PIK3CA (12/21; P <0.004). Undifferentiated p16 ink4a -negative full-thickness precursors were identified in 7/70 (10%) SCC. Four histologically different HPV-independent penile precursor lesions can be assigned to 2 major genetic/biological pathways with characteristic highly differentiated precursors requiring different clinical management decisions. These include d-PeIN in chronic inflammatory dermatoses, with p53 overexpression and TP53/CDKN2A mutations, and the p53 wild-type verrucous and verruciform precursors unassociated with dermatoses, but with mutations in oncogenes PIK3CA and HRAS .

Multiparametric Magnetic Resonance Imaging of Penile Cancer: A Pictorial Review

The role of multiparametric magnetic resonance imaging (mpMRI) in assessing penile cancer is not well defined. However, this modality may be successfully applied for preoperative staging and patient selection; postoperative local and regional surveillance; and assessments of treatment response after oncological therapies. Previous studies have been mostly limited to a few small series evaluating the accuracy of MRI for the preoperative staging of penile cancer. This review discusses the principles of non-erectile mpMRI, including functional techniques and their applications in evaluating the male genital region, along with clinical protocols and technical considerations. The latest clinical classifications and guidelines are reviewed, focusing on imaging recommendations and discussing potential gaps and disadvantages. The development of functional MRI techniques and the extraction of quantitative parameters from these sequences enables the noninvasive assessment of phenotypic and genotypic tumor characteristics. The applications of advanced techniques in penile MRI are yet to be defined. There is a need for prospective trials and feasible multicenter trials due to the rarity of the disease, highlighting the importance of minimum technical requirements for MRI protocols, particularly image resolution, and finally determining the role of mpMRI in the assessment of penile cancer.

Penile intraepithelial neoplasia: Distribution of subtypes, HPV genotypes and p16INK4a in 84 international cases

There are few pathologic or molecular studies of penile precancerous lesions, and the majority refers to lesions associated with invasive carcinomas. Penile Intraepithelial Neoplasia (PeIN) is classified in two morphologically and distinctive molecular groups, non-HPV and HPV-related with special subtypes. The primary purpose of this international series was to classify PeIN morphologically, detect HPV genotypes and determine their distribution according to PeIN subtypes. A secondary aim was to evaluate the p16^INK4a immunostaining as a possible HPV surrogate for high-risk HPV infection in penile precancerous lesions. Samples consisted of 84 PeIN cases, part of a retrospective cross-sectional analysis of 1095 penile carcinomas designed to estimate the HPV DNA prevalence in penile cancers using PCR and p16^INK4a immunostaining. Penile Intraepithelial Neoplasia (PeIN) was classified in HPV-related (basaloid, warty-basaloid, warty, hybrid, and mixed subtypes) and non-HPV-related (differentiated), the former being the most frequent. PeIN subtypes were differentiated (non-HPV-related) and basaloid, warty-basaloid, warty, hybrid and mixed (HPV-related). Basaloid PeIN was the most commonly diagnosed subtype, and HPV16 was the most frequent HPV genotype detected. Warty-basaloid and warty PeIN showed a more heterogeneous genotypic composition. Most HPV genotypes were high-risk but low-risk HPV genotypes were also present in a few cases (4%). A single HPV genotype was detected in 82% of HPV positive cases. In contrast, multiple genotypes were detected in the remaining 18% of cases. The findings in this study support the paradigm that penile in situ neoplasia, like its invasive counterparts, is HPV dependent or independent and has distinctive morphological subtypes readily identified in routine practice. Considering that HPV16 is clearly the predominant type, and that the three available vaccines have HPV16, all of them will be suitable for vaccination programs; the price of the vaccines will be probably the main determinant to choose the vaccine.

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.

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 Association between Tumor Budding Peritumoral and Histologic Grade in Penile Squamous Cell Carcinoma

ABSTRACTIntroduction Squamous cell carcinoma (SCC) is the largest type of Penile Cancer, which is usually lymphomatous that spreads to the inguinal lymph nodes. Inguinal lymph node metastases are the most important factor in predicting survival in penile SCC and therapy choices. Tumor budding is a biological phenomenon that has been described in malignancies and have both predictive and independent significant prognostic. Lack of information about tumor budding in penile SCC. This study determines whether there is a correlation between tumor budding peritumoral with histological grade in penile SCC. Materials and Methods : Samples are taken from the paraffin blocks of patients diagnosed with penile SCC. The tumor budding peritumoral evaluation was classified as less 5 buds  (low grade) and five or more buds (high grade) using H&E staining. Histological grade of penile SCC is assessed based on the WHO, and ISUP grade scoring system evaluated based on nuclear pleomorphism with varying amounts of keratin production, which is divided into 3 grade; grade I (well-differentiated carcinoma), grade II (moderately differentiated carcinoma), grade III (poorly differentiated carcinoma). The correlation of tumor budding peritumoral with histopathological grade in penile SCC was analyzed statistically. Results The mean age of SCC patient was 51.16 years old with range 60-69 years old had the most respondents. The glans penis is the most prevalent site for a tumor, with stage IIIB is being the most dominant stage. The majority of the samples were from lymph node metastases. The majority of peritumoral budding tumors (60.7 percent) had high-grade budding. Conclusions This research discovered a significant correlation between peritumoral budding tumors and grade histopathology of Penile SCC (p-value = 0.0005). Keywords: Tumor budding, peritumoral, histopathological grade, penile SCC

Pathogenesis of Penile Squamous Cell Carcinoma: Molecular Update and Systematic Review

Penile squamous cell carcinoma (PSCC) is a rare but aggressive neoplasm with dual pathogenesis (human papillomavirus (HPV)-associated and HPV-independent). The development of targeted treatment is hindered by poor knowledge of the molecular landscape of PSCC. We performed a thorough review of genetic alterations of PSCC focused on somatic mutations and/or copy number alterations. A total of seven articles have been identified which, overall, include 268 PSCC. However, the series are heterogeneous regarding methodologies employed for DNA sequencing and HPV detection together with HPV prevalence, and include, in general, a limited number of cases, which results in markedly different findings. Reported top-ranked mutations involve TP53, CDKN2A, FAT1, NOTCH-1 and PIK3CA. Numerical alterations involve gains in MYC and EGFR, as well as amplifications in HPV integration loci. A few genes including TP53, CDKN2A, PIK3CA and CCND1 harbor both somatic mutations and copy number alterations. Notch, RTK-RAS and Hippo pathways are frequently deregulated. Nevertheless, the relevance of the identified alterations, their role in signaling pathways or their association with HPV status remain elusive. Combined targeting of different pathways might represent a valid therapeutic approach in PSCC. This work calls for large-scale sequencing studies with robust HPV testing to improve the genomic understanding of PSCC.

Warthy-Basaloid Squamous Cell Carcinoma of Penile - Case Report

Objective

The aim of the study was to present a case of penile squamous cell carcinoma and immunohistochemical identification and evaluation of E-cadherin and β-catenin expression.

Methods

We are presenting a 70-year old man with a variant of penile squamous cell carcinoma with mixed warty and basaloid features. After diagnosis, the patient underwent partial penectomy. Samples taken from the material after surgery were subjected to basic histological staining and immunohistochemical identification of E-cadherin and β-catenin. A Real-time PCR study was conducted to investigate the expression of E-cadherin and β-catenin.

Results

Routine histopathological examinations revealed the characteristic features of warty-basaloid squamous cell carcinoma. In the case studied, a positive immunohistochemical reaction was observed for E-cadherin and β-catenin. QRT-PCR analysis showed a statistically significant decrease in E-cadherin expression in tumor samples compared to healthy tissue. In contrast, expression of the gene encoding β-catenin was slightly higher in tumor samples compared to normal tissue.

Conclusions

The reduced level of the complex of adhesive elements, E-cadherin-β-catenin, disturbs cell differentiation, promotes a more invasive phenotype-stromal infiltration and the formation of distant metastases. In the described case of the penile tumor, a decrease in E-cadherin expression was noted, which could be related to the occurrence of neoplastic infiltration of the spongy body space. In summary, E-cadherin and β-catenin expression and the immunoreactivity of these proteins are expressed at different levels in tumor cells and in penile interstitial cells. Regulation of expression during various physiological and pathophysiological processes indicates a potentially important role of E-cadherin and β-catenin in cell proliferation and adhesion.

Balanitis Xerotica Obliterans Associated With Differentiated Penile Intraepithelial Neoplasia and "Bramble-Bush" Elastic Fibers Accumulation: A Finding Not Specific for Penicillamine Intake

We describe the association of balanitis xerotica obliterans and differentiated penile intraepithelial neoplasia (PeIN) with dermal elastosis and "bramble-bush" elastic fibers in a diabetic patient with no history of penicillamine intake. An 84-year-old man presented with urethral obstruction syndrome that required postectomy, meatotomy, and foreskin excision. Histopathological examination revealed changes of lichen sclerosus and differentiated PeIN. Orcein staining showed striking dermal elastosis and transepidermal elimination of elastic fibers. At higher magnification, multiple serrations and buds arising from the borders of the elastic fibers were observed giving the so-called bramble-bush appearance. Balanitis xerotica obliterans is considered a premalignant disease, and 14% of patients have evidence of PeIN. The differentiated subtype can be difficult to diagnose because of the minimal basal cell atypia, so a striking dermal elastosis, which may even occur before the neoplasm becomes invasive, may facilitate its diagnosis. The term "acquired perforating dermatosis" seems appropriate to describe those cases of perforating elastosis that occurs in adults with systemic diseases. The bramble-bush appearance of elastic fibers is not specific for penicillamine-induced elastopathy, and it may occur in other diseases, such as diabetes mellitus. This peculiar morphology of elastic fibers may be related to the enzymatic imbalance between matrix metalloproteinases and lysyl oxidase, an enzyme required for the cross-linking of elastic fibers.

Whole-exome Sequencing in Penile Squamous Cell Carcinoma Uncovers Novel Prognostic Categorization and Drug Targets Similar to Head and Neck Squamous Cell Carcinoma

PURPOSE

Penile squamous cell carcinoma (PSCC) is rare with limited treatment options. We report the first whole-exome sequencing (WES) analysis and compare the molecular landscape of PSCC with other squamous cell carcinomas (SCC), with the goal to identify common novel targets.

EXPERIMENTAL DESIGN

PSCC and matched normal penile tissues from 34 prospectively followed patients, underwent genomic WES and human papilloma virus testing. We performed tumor mutation signature estimation by two methods, first to identify APOBEC-related mutation enrichments and second to classify PSCC-enriched mutational patterns based on their association with the Catalogue of Somatic Mutations in Cancer mutation signatures. We performed an extensive genomic comparison between our PSCC cohort and other SCCs in The Cancer Genome Atlas studies.

RESULTS

We identified that most PSCC samples showed enrichment for Notch pathway (n = 24, 70.6%) alterations, comparable with head and neck squamous cell carcinoma (HNSC). PSCC mutation signatures are most comparable with HNSC signatures. PSCC samples showed an enrichment of two distinct mutational signatures, the first, associated with oncogenic activity of AID/APOBEC, and the second, associated with defective DNA mismatch repair and microsatellite instability. MP1 enrichment was positively correlated with increased tumor mutation burden (TMB; CC, 0.71; P < 0.0001) and correlated with significantly worse survival in comparison with those with the MP2 subset [HR, 10.2 (1.13-92.9); P = 0.039]. We show that a subset of PSCC (38%), with enrichment of APOBEC-related mutation signature, had significantly higher TMB and worse overall survival in comparison with non-APOBEC-enriched subset [HR, 2.41 (1.11-6.77); P = 0.042].

CONCLUSIONS

This study identified novel druggable targets and similarities in mutational signatures between PSCC and HNSC with potential clinical implications.See related commentary by McGregor and Sonpavde, p. 2375.

Update on the Diagnosis of Sexually Transmitted Infections

Sexually transmitted infections (STIs) are one of the most frequent and universal Public Health problems. Health professionals should be aware of the possibility of STIs due to their high morbidity and the presence of sequelae. The delay in the diagnosis is one of the factors that justifies the difficulty to infections control. Diagnostic tests allow the introduction of aetiological treatment and also lead to treating symptomatic and asymptomatic patients more effectively, as well as to interrupt the epidemiological transmission chain without delay. In this review we have made an update of the main existing diagnostic methods for the more important STIs.

Prevalence of human papillomavirus and implication on survival in Chinese penile cancer

We assessed the prevalence of HPV DNA in a large series of Chinese penile cancer and examine its association with the histological subtype, p16^INK4a expression, and prognosis. We pathologically categorized 226 invasive penile squamous cell carcinomas and assessed HPV genotyping by real-time PCR and p16^INK4a immunohistochemistry. The results were correlated with histopathological and clinical parameters and disease-specific survival (DSS). HPV DNA was detected in 32.7% (74/226) of penile cancer cases. The most frequent genotype was HPV 16 (64/74, 86.5%), followed by HPV 18 (6/74, 8.1%). Fifty-nine (26.1%) cases were positive for the p16^INK4a expression, and p16^INK4a expression had a sensitivity of 56.8% (95% CI, 45.2-68.3%) and a specificity of 88.8% (95% CI, 83.8-93.9%) for defining HPV status. HPV DNA (P = 0.019), p16^INK4a (P = 0.038), age (P = 0.018), grade of differentiation (P = 0.001), lymph nodes (P < 0.001), T stage (P < 0.001), M stage (P < 0.001), and lymphovascular invasion (LVI, P = 0.001) were prognostic factors for DSS. HPV-positivity (HR 0.334; 95% CI, 0.158-0.705, P = 0.004) was still a significant prognostic factor for DSS in the multivariate Cox regression model. HPV DNA was observed in one third of Chinese penile carcinoma cases. The p16INK4a expression can indicate high-risk human papillomavirus (HR-HPV). HPV-positive penile tumors confer a survival benefit over HPV-negative tumors.

Comparison of Human Papillomavirus Genotypes in Penile Intraepithelial Neoplasia and Associated Lesions: LCM-PCR Study of 87 Lesions in 8 Patients

Penile intraepithelial neoplasia (PeIN) is currently classified in human papillomavirus (HPV)- and non-HPV-related subtypes with variable HPV genotypes. PeINs are frequently associated with other intraepithelial lesions in the same specimen. The aim of this study was to detect and compare HPV genotypes in PeINs and associated lesions using high-precision laser capture microdissection-polymerase chain reaction and p16^INK4a immunostaining. We evaluated resected penile specimens from 8 patients and identified 33 PeINs and 54 associated lesions. The most common subtype was warty PeIN, followed by warty-basaloid and basaloid PeIN. Associated lesions were classical condylomas (17 cases), atypical classical condylomas (2 cases), flat condylomas (9 cases), atypical flat condylomas (6 cases), flat lesions with mild atypia (12 cases), and squamous hyperplasia (8 cases). After a comparison, identical HPV genotypes were found in PeIN and associated lesions in the majority of the patients (7 of 8 patients). HPV16 was the most common genotype present in both PeIN and corresponding associated lesion (50% of the patients). Nonspecific flat lesions with mild atypia, classical condylomas, and atypical condylomas were the type of associated lesions most commonly related to HPV16. Other high-risk HPV genotypes present in PeIN and associated nonspecific flat lesion with mild atypia were HPV35 and HPV39. In this study of HPV in the microenvironment of penile precancerous lesions, we identified identical high-risk HPV genotypes in PeIN and classical, flat, or atypical condylomas and, specially, in nonspecific flat lesions with mild atypia. It is possible that some of these lesions represent hitherto unrecognized precancerous lesions.

Morphology, p16, HPV, and outcomes in squamous cell carcinoma of the penis: a multi-institutional study

Our objective was to evaluate the pathologic features and clinical outcomes in cases of invasive penile squamous cell carcinoma (SCC) and the association with p16 immunohistochemistry (IHC) and human papilloma virus (HPV) in situ hybridization (ISH). A retrospective multi-institutional database search was conducted for invasive SCC of the penis diagnosed between 2007 and 2018 that had undergone surgical resection. Pathologic features, p16 IHC, and HPV ISH were investigated with clinical outcomes. A total of 102 patients were included in the study. The average age was 63 ± 13.3 years. Based on histology, 46% of tumors displayed an HPV-related subtype, whereas p16 was positive in 52% of all cases. Tumor histology correlated well with p16 positivity (P < .001), and p16 IHC accurately predicted the presence of HPV in 25/26 (96%) cases. On multivariate analysis, perineural invasion was associated with local disease recurrence (P = .02), whereas lymphovascular invasion was associated with progression to metastatic disease (P = .002) and increased overall mortality (P = .02). Urethral involvement was also associated with increased overall mortality (P = .02). In addition, HPV-related tumors based on histologic features correlated with lower rates of metastatic disease (P = .007). HPV is a common cause of penile SCC and can be diagnosed by tumor histology and confirmed by overexpression of p16 on IHC. The presence of lymphovascular invasion, perineural invasion, and urethral involvement are poor prognostic indicators, whereas HPV-related tumors based on histology may have lower risk for metastatic disease.

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.

Topical Therapy for non-invasive penile cancer (Tis)-updated results and toxicity

Penile cancer is a rare malignancy estimated to affect 26,000 men globally each year. The association with penile cancer, in particular non-invasive disease, and human papilloma virus (HPV) is well known. Ninety-five percent of cases of penile cancer are squamous cell carcinoma (SCC), which are staged using the TNM staging system. Terminology describing the histological appearance of non-invasive penile cancer has changed with all cases grouped under the umbrella term of penile intraepithelial neoplasia (PeIN); either undifferentiated or differentiated. This replaces previous terms such as carcinoma in situ (CIS) and eponymous names such as Bowen's disease. This change is recognised by the World Health Organisation (WHO). The topical treatments most commonly used for PeIN are 5-fluorouracil (5-FU) and imiquimod (IQ). Other treatments such as photodynamic therapy (PDT) are used but to a lesser degree. The evidence for all of these treatments is heterogenous with no randomised data available. Overall up to 57% complete response has been reported with a low number of serious adverse events. In this article, we aim to review the available evidence for the topical treatment of non-invasive penile cancer specifically regarding its efficacy and toxicity.

Cutaneous Squamous Cell Carcinoma: Review of the Eighth Edition of the American Joint Committee on Cancer Staging Guidelines, Prognostic Factors, and Histopathologic Variants

Cutaneous squamous cell carcinoma is the second most common form of nonmelanoma skin cancer after basal cell carcinoma and accounts for the majority of nonmelanoma skin cancer-related deaths. In 2017, the American Joint Committee on Cancer revised the staging guidelines of cutaneous squamous cell carcinoma to reflect recent evidence concerning high-risk clinicopathologic features. This update reviews the literature on prognostic features and staging, including the eighth edition of the American Joint Committee on Cancer Staging Manual. A wide range of histopathologic variants of cutaneous squamous cell carcinoma exists, several of which are associated with aggressive behavior. A review of cutaneous squamous cell carcinoma variants, emphasizing diagnostic pitfalls, immuhistochemical findings and prognostic significance, is included. Of note, the eighth edition of the American Joint Committee on Cancer Staging Manual refers to squamous cell carcinoma of the head and neck only.

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.

Pathologic and imunohistochemical characterization of tumoral inflammatory cell infiltrate in invasive penile squamous cell carcinomas: Fox-P3 expression is an independent predictor of recurrence

Penile carcinomas (PeCa) are relatively rare, but devastating neoplasms, more frequent among people of underprivileged socioeconomic status. There is mounting evidence that immune cells may trigger various mechanisms that enhance tumor growth and metastasis, but no data on the peritumoral inflammation is available for PeCa. The objectives of the present study are to evaluate the immunohistomorphology of tumoral inflammation in PeCa, and to correlate it with clinicopathological parameters, which could contribute to the prognostic evaluation. One hundred and twenty-two patients with the diagnosis of usual-type squamous cell penile carcinoma were included. Paraffin-embedded tissue was submitted to immunohistochemical evaluation of p16 protein, CD3, CD4, CD8, CD20, CD68, CD138, granzyme B, and Fox-P3. The Fisher's exact test was employed for comparison between histological variables and parameters, and the Kaplan-Meier method for the analysis of survival. Improved 5-year overall survival was significantly associated to age ≤60 years, stage I + II, tumor size T1 + T2, lymph node status N0, and absent perineural invasion. In a multivariate analysis age ≥60 years, presence of lymph node metastasis, urethral invasion, and high histologic grade retained a significantly more unfavorable outcome. Improved 5-year failure free survival was associated to stage of the disease I + II, lymph node status N0, absence of perineural, vascular, and urethral invasion, and Fox-P3 expression. In a multivariate analysis, presence of lymph node metastasis, perineural and vascular invasion, and of Fox-P3-positive lymphocytes together with low inflammatory infiltrate retained a significantly more unfavorable outcome. These results support the prognostic value of determining the levels of Fox-P3-positive lymphocytes by immunohistochemistry in PeCa, as this parameter adds value to the traditional clinicopathological features.

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.

P16INK4A immunohistochemistry for detection of human papilloma virus-associated penile squamous cell carcinoma is superior to in-situ hybridization

We evaluated p16INK4A as a reliable option to detect human papilloma virus (HPV) DNA in penile tumor specimens. Formalin-fixed paraffin embedded samples of 26 patients with penile cancer and another 18 cases with non-tumorigenic lesions were stained by three different widely used commercially available chromogenic in-situ hybridization assays high-risk HPV CISH Y1443 (Genpoint, DAKO), pan HPV CISH Y1404 (Genpoint, DAKO), INFORM HPV III (Ventana, Tucson, Arizona) and p16INK4A immunohistochemistry, then compared to the known gold standard polymerase chain reaction detecting HPV 16, 18, 31, and 33. Immunoreactivity for p16INK4A was evaluated by using a 4-tiered (0, 1, 2, and 3) pattern based system. 19 cases were positive for p16INK4A, 13 of which showed a continuous transepithelial staining (pattern 3). Pan HPV ISH showed positivity in 9 cases, high-risk HPV ISH in 7 cases and INFORM HPVIII ISH in 7 cases. p16INK4A IHC pattern 3 versus pattern 0, 1 and 2 exhibited a specificity and positive predictive value of 100 percent, with a sensitivity and negative predictive value of 72 and 62 percent, respectively, which was much better than all HPV in-situ hybridization methods referred to polymerase chain reaction. p16INK4A seems to be a superior marker for the detection of HPV-associated penile squamous cell carcinoma compared to CISH tests, but is not recommend for the detection of non-tumorigenic lesions, where PCR should be used for the initial assessment.

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.

p16 expression is not associated with human papillomavirus in urinary bladder squamous cell carcinoma

Squamous cell carcinoma of the urinary bladder is unusual and of unknown etiology. There is a well-established association between human papillomavirus (HPV) infection and the development of cervical and head/neck squamous cell carcinomas. However, the role of HPV in the pathogenesis of squamous cell carcinoma of the urinary bladder is uncertain. The purposes of this study were to investigate the possible role of HPV in the development of squamous cell carcinoma of the urinary bladder and to determine if p16 expression could serve as a surrogate marker for HPV in this malignancy. In all, 42 cases of squamous cell carcinoma of the urinary bladder and 27 cases of urothelial carcinoma with squamous differentiation were investigated. HPV infection was analyzed by both in situ hybridization at the DNA level and immunohistochemistry at the protein level. p16 protein expression was analyzed by immunohistochemistry. HPV DNA and protein were not detected in 42 cases of squamous cell carcinoma (0%, 0/42) or 27 cases of urothelial carcinoma with squamous differentiation (0%, 0/15). p16 expression was detected in 13 cases (31%, 13/42) of squamous cell carcinoma and 9 cases (33%, 9/27) of urothelial carcinoma with squamous differentiation. There was no correlation between p16 expression and the presence of HPV infection in squamous cell carcinoma of the bladder or urothelial carcinoma with squamous differentiation. Our data suggest that HPV does not play a role in the development of squamous cell carcinoma of the urinary bladder or urothelial carcinoma with squamous differentiation. p16 expression should not be used as a surrogate marker for evidence of HVP infection in either squamous cell carcinoma of the urinary bladder or urothelial carcinoma with squamous differentiation as neither HVP DNA nor protein is detectable in these neoplasms.

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.

Lichen sclerosus and squamous cell carcinoma

Lichen sclerosus is a chronic inflammatory disease that can progress to malignancy. The literature indicates an association with anogenital squamous cell carcinoma and verrucous carcinoma. Two pathogenic pathways, differentiated vulvar and penile intraepithelial neoplasias, which have recently been described in relation to squamous cell carcinoma, are both highly associated with genital lichen sclerosus independently of human papilloma virus (HPV) infection. Furthermore, tumor-promoting molecular changes unrelated to HPV infection have been demonstrated and may explain the malignant potential of lichen sclerosus. The possible relationship between HPV and genital lichen sclerosus currently remains open to discussion, and the prognostic importance of the overlapping of these 2 diseases is still unclear. This review considers the relationship between lichen sclerosus and squamous cell and verrucous carcinomas, the possible oncogenic mechanisms involved, and their possible association with HPV infection.