Lymphoepithelioma-like carcinoma of the penis: association with human papilloma virus infection

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 cancer: ESMO-EURACAN Clinical Practice Guideline for diagnosis, treatment and follow-up

•This ESMO CPG provides recommendations for diagnosis, staging, pathology, treatment and follow-up of penile cancer. •Algorithms for the management of primary penile tumours and inguinal lymph nodes are provided. •The author group encompasses a multidisciplinary group of experts from different institutions and countries in Europe. •Recommendations are based on available scientific data and the authors’ collective expert opinion. •In clinical practice, all recommendations provided need to be discussed with patients in a shared decision-making approach.

Detection of variable genotypes in common human papillomavirus-associated invasive penile squamous cell carcinomas: a study of 177 human papillomavirus-positive cases

Human papillomavirus (HPV) is detected in 30-50% of invasive penile carcinomas, and it is frequently associated with basaloid and warty morphological features. Based on this heterogeneity and different clinical behaviors, we hypothesized a variation in their HPV genotypic composition. To test this, we evaluated 177 HPV-positive cases: basaloid (114), warty-basaloid (28), and warty (condylomatous) (35) invasive carcinomas. HPV DNA detection and genotyping was performed using the SPF-10/DEIA/LiPA25 system. Nineteen HPV genotypes were detected. High-risk HPVs predominated (96%), and low-risk HPVs were rarely present. Most common genotype was HPV16 followed by HPVs 33 and 35. According to the genotypes identified, 93% of the cases would be covered with current vaccination programs. There was a significant variation in the distribution of HPV16 and non-HPV16 genotypes according to histological subtype. HPV16 was significantly frequent in basaloid (87%) and was less frequent in warty carcinomas (61%). This molecular difference, along with their distinctive macro-microscopic and prognostic features, makes basaloid and warty carcinomas unique. The gradual decreasing frequency of HPV16 demonstrated in basaloid, warty-basaloid, and warty carcinomas suggest that the basaloid cell, present in those types in decreasing proportions, may be responsible for the differences.

The 2022 World Health Organization Classification of Tumours of the Urinary System and Male Genital Organs-Part A: Renal, Penile, and Testicular Tumours

The fifth edition of the World Health Organization (WHO) classification of urogenital tumours (WHO "Blue Book"), published in 2022, contains significant revisions. This review summarises the most relevant changes for renal, penile, and testicular tumours. In keeping with other volumes in the fifth edition series, the WHO classification of urogenital tumours follows a hierarchical classification and lists tumours by site, category, family, and type. The section "essential and desirable diagnostic criteria" included in the WHO fifth edition represents morphologic diagnostic criteria, combined with immunohistochemistry and relevant molecular tests. The global introduction of massive parallel sequencing will result in a diagnostic shift from morphology to molecular analyses. Therefore, a molecular-driven renal tumour classification has been introduced, taking recent discoveries in renal tumour genomics into account. Such novel molecularly defined epithelial renal tumours include SMARCB1-deficient medullary renal cell carcinoma (RCC), TFEB-altered RCC, Alk-rearranged RCC, and ELOC-mutated RCC. Eosinophilic solid and cystic RCC is a novel morphologically defined RCC entity. The diverse morphologic patterns of penile squamous cell carcinomas are grouped as human papillomavirus (HPV) associated and HPV independent, and there is an attempt to simplify the morphologic classification. A new chapter with tumours of the scrotum has been introduced. The main nomenclature of testicular tumours is retained, including the use of the term "germ cell neoplasia in situ" (GCNIS) for the preneoplastic lesion of most germ cell tumours and division from those not derived from GCNIS. Nomenclature changes include replacement of the term "primitive neuroectodermal tumour" by "embryonic neuroectodermal tumour" to separate these tumours clearly from Ewing sarcoma. The term "carcinoid" has been changed to "neuroendocrine tumour", with most examples in the testis now classified as "prepubertal type testicular neuroendocrine tumour".

[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.

What Is New in the Pathologic Staging of Penile Carcinoma in the 8th Edition of AJCC TNM Model: Rationale for Changes With Practical Stage-by-stage Category Diagnostic Considerations

For >50 years the tumor, node, metastasis (TNM) classification model of malignant tumors has been the main resource for clinicians, pathologists, radiologists and public health professionals ensuring a homogeneous classification and patients' management based on common staging and prognosis factors. Penile cancer was first included for staging in the third edition of the TNM classification with several changes in the last version, the 8th edition of the AJCC TNM Manual, in 2017. Some changes in the pT category were done due to recent knowledge regarding the prognostic importance of anatomical level of invasion, vascular and perineural invasion and tumor grading. These changes must be interpreted in the light of a required understanding of the complex anatomy of penile compartments especially their histological boundaries, the morphological differences of each level needed for the correct classification, the heterogeneity of penile squamous cell carcinomas and an adequate criticism of the current model used by the TNM system. We present here a series of stage-by-stage category diagnostic considerations based on the clinical experience acummulated over the years of applying the different TNM staging classifications in our large clinical practice. Some discrepancies will need well-designed prospective studies for im4proving the actual classification.

Experimental Models for Studying HPV-Positive and HPV-Negative Penile Cancer: New Tools for An Old Disease

Simple Summary

Penile cancer is an uncommon and understudied malignancy that is most commonly diagnosed in developing countries. Therapeutic advances have been slow, in part due to the lack of in vitro and in vivo models for testing new drugs before performing clinical trials. Recently, this difficulty has been partly overcome and multiple new pre-clinical models were reported. These important developments will help develop new therapies for penile cancer patients. The present review summarizes and discusses the available data concerning the pre-clinical models of penile cancer and their uses. Comparisons are drawn between different models, allowing researchers to choose the most adequate setting for their experiments. The remaining gaps in this array of penile cancer models are also discussed, in particular the lack of models for studying metastatic disease and cell lines representing tumors associated with human papillomavirus.

Abstract

Penile cancer is an uncommon malignancy that occurs most frequently in developing countries. Two pathways for penile carcinogenesis are currently recognized: one driven by human papillomavirus (HPV) infection and another HPV-independent route, associated with chronic inflammation. Progress on the clinical management of this disease has been slow, partly due to the lack of preclinical models for translational research. However, exciting recent developments are changing this landscape, with new in vitro and in vivo models becoming available. These include mouse models for HPV⁺ and HPV⁻ penile cancer and multiple cell lines representing HPV⁻ lesions. The present review addresses these new advances, summarizing available models, comparing their characteristics and potential uses and discussing areas that require further improvement. Recent breakthroughs achieved using these models are also discussed, particularly those developments pertaining to HPV-driven cancer. Two key aspects that still require improvement are the establishment of cell lines that can represent HPV⁺ penile carcinomas and the development of mouse models to study metastatic disease. Overall, the growing array of in vitro and in vivo models for penile cancer provides new and useful tools for researchers in the field and is expected to accelerate pre-clinical research on this disease.

Penile Lymphoepithelioma-Like Carcinoma: A Rare Case With PD-L1 Expression

Most malignant tumors of the penis are squamous cell carcinomas (SCC), being divided in 2 groups, one human papillomavirus (HPV)-related and another non-HPV-related, with lymphoepithelioma-like carcinoma (LELC) being one of the rarest HPV-related SCC. In this article, we report a case of a 50-year-old man who presented testicular swelling and pain for the past 3 months. A penile mass was identified, and the patient was submitted to a total penectomy. The penectomy specimen showed an ulcerated lesion at the glans reaching the cavernous bodies. Microscopic examination showed undifferentiated epithelial cells with syncytial growth pattern mix with a dense lymphoplasmacytic infiltrate, consistent with LELC. The tumor cells expressed p16 and all 3 different clones of PDL1 (22C3, SP263, and SP142). The patient is alive and well with a follow-up of 3 months. To our knowledge, this is the third LELC of the penis reported in literature and the first case reported with PDL1 expression.

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

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

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.

Pathology of Invasive and Intraepithelial Penile Neoplasia

Since 1995 it has been known that tumors harboring human papillomavirus (HPV) preferentially show basaloid or condylomatous histological features, while HPV-negative tumors have a different morphology. New classification models separate subtypes of penile squamous cell carcinomas in two groups, non-HPV- and HPV-related. It is purported that HPV-related tumors have better prognosis. Other features such as inflammatory cell-rich medullary, clear-cell, and lymphoepithelioma-like patterns are also strong predictors of the presence of HPV. These tumors are morphologically distinctive and with some experience, pathologists may recognize them after routine hematoxylin and eosin staining. Occasionally, p16 immunostaining may aid in differential diagnosis. The gold standard for HPV detection is polymerase chain reaction, but this technique is expensive and not available in most pathology laboratories. In situ hybridization is useful and p16 immunostaining can detect HPV in approximately 85% of cases. There is correlation between morphology and outcome. PATIENT SUMMARY: This mini review provides an overview of the latest classification for penile invasive carcinoma and penile intraepithelial neoplasia.

The World Health Organisation 2016 classification of penile carcinomas: a review and update from the International Society of Urological Pathology expert-driven recommendations

The International Society of Urological Pathology (ISUP) held an expert-driven penile cancer conference in Boston in March 2015, which focused on the new World Health Organisation (WHO) classification of penile cancer: human papillomavirus (HPV)-related tumours and histological grading. The conference was preceded by an online survey of the ISUP members, and the results were used to initiate discussions. Because of the rarity of penile tumours, this was not a consensus but an expert-driven conference aimed at assisting pathologists who do not see these tumours on a regular basis. After a justification for the novel separation of penile squamous cell carcinomas into HPV-related and non-HPV-related-carcinomas, the histological classification of penile carcinoma was proposed; this system was also accepted subsequently by the WHO for subtyping of penile carcinomas (2016). A description of HPV-related neoplasms, which may be recognised by their histological features, was presented, and p16 was recommended as a surrogate indicator of HPV. A three-tier grading system was recommended for penile squamous carcinomas; this was also adopted by the WHO (2016). Many of the distinctive histological subtypes of squamous cell carcinoma of the penis are associated with distinct grades, based on the squamous cell carcinoma subtype histological features.

Clear Cell Carcinoma of the Penis: An HPV-related Variant of Squamous Cell Carcinoma: A Report of 3 Cases

Penile clear cell carcinoma originating in skin adnexal glands has been previously reported. Here, we present 3 morphologically distinctive penile tumors with prominent clear cell features originating not in the penile skin but in the mucosal tissues of the glans surface squamous epithelium. Clinical and pathologic features were evaluated. Immunohistochemical stains were GATA3 and p16. Human papilloma virus (HPV) detection by in situ hybridization was performed in 3 cases, and whole-tissue section-polymerase chain reaction was performed in 1 case. Patients' ages were 52, 88, and 95 years. Tumors were large and involved the glans and coronal sulcus in all cases. Microscopically, nonkeratinizing clear cells predominated. Growth was in solid nests with comedo-like or geographic necrosis. Focal areas of invasive warty or basaloid carcinomas showing in addition warty or basaloid penile intraepithelial neoplasia were present in 2 cases. There was invasion of corpora cavernosa, lymphatic vessels, veins, and perineural spaces in all cases. p16 was positive, and GATA3 stain was negative in the 3 cases. HPV was detected in 3 cases by in situ hybridization and in 1 case by polymerase chain reaction. Differential diagnoses included other HPV-related penile carcinomas, skin adnexal tumors, and metastatic renal cell carcinoma. Features that support primary penile carcinoma were tumor location, concomitant warty and/or basaloid penile intraepithelial neoplasia, and HPV positivity. Clinical groin metastases were present in all cases, pathologically confirmed in 1. Two patients died from tumor dissemination at 9 and 12 months after penectomy. Clear cell carcinoma, another morphologic variant related to HPV, originates in the penile mucosal surface and is probably related to warty carcinomas.

The 2016 WHO Classification of Tumours of the Urinary System and Male Genital Organs-Part A: Renal, Penile, and Testicular Tumours

The fourth edition of the World Health Organization (WHO) classification of urogenital tumours (WHO "blue book"), published in 2016, contains significant revisions. These revisions were performed after consideration by a large international group of pathologists with special expertise in this area. A subgroup of these persons met at the WHO Consensus Conference in Zurich, Switzerland, in 2015 to finalize the revisions. This review summarizes the most significant differences between the newly published classification and the prior version for renal, penile, and testicular tumours. Newly recognized epithelial renal tumours are hereditary leiomyomatosis and renal cell carcinoma (RCC) syndrome-associated RCC, succinate dehydrogenase-deficient RCC, tubulocystic RCC, acquired cystic disease-associated RCC, and clear cell papillary RCC. The WHO/International Society of Urological Pathology renal tumour grading system was recommended, and the definition of renal papillary adenoma was modified. The new WHO classification of penile squamous cell carcinomas is based on the presence of human papillomavirus and defines histologic subtypes accordingly. Germ cell neoplasia in situ (GCNIS) of the testis is the WHO-recommended term for precursor lesions of invasive germ cell tumours, and testicular germ cell tumours are now separated into two fundamentally different groups: those derived from GCNIS and those unrelated to GCNIS. Spermatocytic seminoma has been designated as a spermatocytic tumour and placed within the group of non-GCNIS-related tumours in the 2016 WHO classification.

PATIENT SUMMARY

The 2016 World Health Organization (WHO) classification contains new renal tumour entities. The classification of penile squamous cell carcinomas is based on the presence of human papillomavirus. Germ cell neoplasia in situ of the testis is the WHO-recommended term for precursor lesions of invasive germ cell tumours.