High-risk human papilloma virus status & outcomes for penile squamous cell carcinoma: A single institution experience.

OBJECTIVES: There is a paucity of data on North American cohorts of patients with penile squamous cell carcinoma (pSCC). Herein, we aimed to assess the sensitivity of various modalities to identify human papillomavirus (HPV) status, determine the prevalence of high-risk HPV-positivity, and evaluate the prognostic impact of relevant clinicopathologic variables. METHODS: Patients with pSCC (n = 121) consecutively treated with partial/total penectomy (2000-2022) at a single institution were included. HPV status (based on immunohistochemistry [IHC], in situ hybridization [ISH], and panviral metagenomic sequencing [PMS]), histologic features, and outcomes were reviewed. Outcome events included death due to disease and progression. RESULTS: The majority of patients were white (105/121, 86.8%). Thirty-seven (30.6%) were high-risk HPV-positive, and morphologic evaluation had a sensitivity of 97.3% (95% confidence interval [CI], 86.2-99.5) for predicting high-risk HPV status compared to IHC/ISH/PMS. Disease progression was more common among high-risk HPV-negative compared to high-risk HPV-positive patients (HR 2.74, CI 1.12-8.23, P = 0.03). Moreover, among high-risk HPV-negative patients, those with moderate-poorly differentiated tumors had increased disease-specific mortality (32.6%, CI 17.1-48.1) compared to those with well-differentiated tumors (0%). Among high-risk HPV-positive patients, those with basaloid morphology had lower disease-specific mortality (0% vs 14.4%, CI 0.0-33.1). CONCLUSIONS: We demonstrate high-risk HPV-positivity in approximately one-third of patients with pSCC. Morphologic evaluation alone had a high sensitivity in correctly determining HPV status. Our results suggest that high-risk HPV status and morphologic features (differentiation in high-risk HPV-negative, and basaloid subtype in high-risk HPV-positive pSCC) may have prognostic value.

Comparison of a modified staging system with 8th edition AJCC criteria in a North American cohort of pT2/pT3 HPV-negative penile squamous cell carcinoma.

The staging for pT2/pT3 penile squamous cell carcinoma (pSCC) has undergone major changes. Some authors proposed criteria wherein the distinction between pT2/pT3 was made using the same histopathological variables that are currently utilized to differentiate pT1a/pT1b. In this single-institution, North American study, we focused on (HPV-negative) pT2/3 pSCCs (i.e., tumors invading corpus spongiosum/corpus cavernosum), and compared the prognostic ability of the following systems: (i) AJCC (8th edition) criteria; (ii) modified staging criteria proposed by Sali et al. (Am J Surg Pathol. 2020; 44:1112-7). In the proposed system, pT2 tumors were defined as those devoid of lymphovascular invasion (LVI) or perineural invasion (PNI), and were not poorly differentiated; whereas pT3 showed one or more of the following: LVI, PNI, and/or grade 3. 48 pT2/pT3 cases were included (AJCC, pT2: 27 and pT3: 21; Proposed, pT2: 22 and pT3: 26). The disease-free survival (DFS) and progression-free survival (PFS) did not differ between pT2 and pT3, following the current AJCC definitions (p = 0.19 and p = 0.10, respectively). When the pT2/3 stages were reconstructed using the modified criteria, however, a statistically significant difference was present in both DFS and PFS between pT2 and pT3 (p = 0.004 and p = 0.003, respectively). The proposed staging system has the potential to improve the prognostication of pT2/pT3 tumors in pSCC. Each of these histopathologic variables has been shown to have a significant association with outcomes in pSCC, which is an advantage. Further studies are needed to demonstrate the utility of this modified staging system in patient populations from other geographic regions.

Gradual and synergistic correlation of tumor thickness and histological grade in penile invasive carcinomas.

Histological grade and depth of invasion are among the best outcome pathological predictors in penile cancer. The TNM system is based on a combination of both for some stages. It is assumed that high-grade and deep tumors carry the worst prognosis, and the opposite occurs with superficial and low-grade neoplasms. However, there is no systematic evaluation of the phenomenon. We studied 147 patients from the Hospital de Oncologia - Instituto Mexicano del Seguro Social (period 2000 to 2013). They were treated by total or partial penectomies. Lymph node involvement was evaluated by bilateral inguinal node dissection (126 cases) or ultrasonography (21 cases). Tumor thickness was measured in mm from tumor surface to deepest invasion point, using a cut-point for superficial (≤10 mm) vs deep (>10 mm) tumors. Histological grade was from 1 to 3 according to WHO and AFIP criteria and considering G1 and G2 as low-grade and G3 as high-grade. Average age was 62 (26-98) years old. Tumor thickness mean was 15 mm (2-30 mm). G1, G2 and G3 tumors corresponded to 19 (13 %), 48 (33 %), and 80 (54 %) cases, respectively. Follow-up ranged from 10 to 82 months (median: 57 months). Fifty-three (36 %) patients died of disease. There was an overall correlation of tumor thickness and grade in most of the cases. Low-grade tumors were encountered in 92 % (12/13 cases) of superficial tumors. Deep tumors showed high-grade in 75 % of cases (73/97 cases). Superficial tumors with low histological grade had negative inguinal nodes and no mortality whereas deep tumors showing high histological grade were associated with high metastatic risk to lymph nodes (62/73 cases) and mortality (52/73 cases). Out of 24 deep tumors with low histological grade, seven had nodal spread (29 %) but only one died of disease. No outcome difference was found in HPV associated vs HPV independent tumors. Tumor thickness and grade are important synergistic and predictive pathological factors in relation to prognosis.

Assessment of PD-L1, TROP2, and nectin-4 expression in penile squamous cell carcinoma.

OBJECTIVES: There is an unmet need for therapeutically relevant biomarkers for advanced penile squamous cell carcinoma (pSCC). Proposed immunohistochemistry (IHC)-based biomarkers include programmed death-ligand 1 (PD-L1), trophoblast cell-surface antigen 2 (TROP2), and nectin-4; however, there is a paucity of data pertaining to these biomarkers. Herein, we investigated the expression of PD-L1, TROP2, and nectin-4 in a well-annotated cohort of pSCCs. METHODS: A single-institution pathology archive was queried for patients who had a partial or total penectomy for pSCC between January 2000 and December 2022. Whole-slide sections were stained with antibodies against PD-L1 (22C3), TROP2, and nectin-4. Expression in tumor cells was quantified using H-scores (0-300). Associations between IHC expression, human papilloma virus (HPV) status, clinicopathologic findings, and outcome parameters were evaluated. RESULTS: This study included 121 patients. For PD-L1, the median combined positive and H-scores were 1 and 0, respectively; 32.7 % of the cases had an H-score>0. Compared to PD-L1-negative tumors, PD-L1-positive tumors had higher pT stage and grade. The median TROP2 and nectin-4 H-scores were 230 and 140, respectively, with high TROP2 and nectin-4, defined by an H-score>200, noted in 80.7 % and 10.9 % of cases, respectively. High-risk HPV-positive cases had higher TROP2 and nectin-4 scores compared to HPV-negative cases. Patients with high TROP2 expression had significantly more disease progression, and patients with high nectin-4 expression had significantly fewer deaths due to disease. CONCLUSIONS: High expression of TROP2 and nectin-4 in pSCC support evaluation of these markers as therapeutic targets pending validation of our findings.

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.

Proteomic and Clinicopathologic Assessment of Penile Amyloidosis: A Single Institutional Review of 12 Cases.

OBJECTIVES: There is a paucity of data on penile amyloidosis. We aimed to assess the frequency of different amyloid types in surgical specimens from the penis involved by amyloidosis and correlate relevant clinicopathologic parameters with proteomic findings. METHODS: Since 2008, our reference laboratory has performed liquid chromatography/tandem mass spectrometry (LC-MS/MS) for amyloid typing. The institutional pathology archive and reference laboratory database were queried to retrospectively identify all penile surgical pathology specimens with LC-MS/MS results between January 1, 2008, and November 23, 2022. Archived H&E-stained and Congo red-stained sections were re-reviewed. RESULTS: Twelve cases of penile amyloidosis were identified, which represented 0.35% (n = 3,456) of penile surgical specimens. AL-type amyloid was most frequent (n = 7), followed by keratin-type amyloid (n = 3) and ATTR (transthyretin)-type amyloid (n = 2). AL-type amyloid cases often showed diffuse dermal/lamina propria deposition, whereas all keratin-type amyloid cases were localized to the superficial dermis. Two cases with keratin-type amyloid had concomitant cutaneous findings (penile intraepithelial neoplasia and condyloma). CONCLUSIONS: This series, the largest to date, demonstrates that penile amyloidosis has a heterogeneous proteomic landscape. To the best of our knowledge, this is the first study describing ATTR (transthyretin)-type penile amyloid.

Penile squamous cell carcinoma exclusive to the shaft, with a proposal for a novel staging system.

Penile squamous cell carcinomas (SCC) originating in the shaft are rare. pT1/pT2 categories in the American Joint Committee on Cancer (AJCC) staging manual (8th edition) are poorly defined for SCCs arising in the dorsal shaft as anatomic structures differ between the glans and dorsal shaft (corpus spongiosum vs dartos/Buck's fascia, respectively). We reviewed six penile SCC cases exclusive to the shaft, an unusual presentation, identified amongst 120 patients treated with penectomy. We propose a novel pT staging system for dorsal shaft tumors tailored to its anatomic landmarks, where tumors extending to Buck's fascia are considered pT2 instead of pT1. The mean age at penectomy, average duration of follow-up, and mean depth of invasion were 64 years, 45 months, and 9.8 mm, respectively. Four cases were moderately differentiated, HPV-negative SCCs of the usual type and two cases were HPV-positive basaloid and warty-basaloid carcinomas. Three cases had nodal or distant metastasis at the time of penectomy, and histologic assessment in these cases showed invasion into the Buck's fascia or deeper. According to the current AJCC system, only one of these three cases would be staged as ≥ pT2. In contrast, all three metastatic tumors would be staged as ≥ pT2 in the proposed model. At last follow-up, one patient died of disease-related complications. Based on this limited series, the proposed staging model appears to suggest better patient stratification for pT1/pT2 stages. This model incorporates Buck's fascia, which has been postulated as a pathway of tumor infiltration. Additional studies are needed to validate this model.

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 p16INK4a 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 p16INK4a 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.

The dual pathogenesis of penile neoplasia: The heterogeneous morphology of human papillomavirus-related tumors.

Objective: Penile neoplasia, usually of squamous histogenesis, is currently classified into human papillomavirus (HPV)-related or -dependent and non-HPV-related or -independent. There are distinct morphological differences among the two groups. New research studies on penile cancer from Northern countries showed that the presence of HPV is correlated with a better prognosis than virus negative people, while studies in Southern countries had not confirmed, perhaps due to differences in staging or treatment. Methods: We focused on the description of the HPV-related carcinomas of the penis. The approach was to describe common clinical features followed by the pathological features of each entity or subtype stressing the characteristics for differential diagnosis, HPV genotypes, and prognostic features of the invasive carcinomas. Similar structure was followed for penile intraepithelial neoplasia, except for prognosis because of the scant evidence available. Results: Most of HPV-related lesions can be straightforwardly recognized by routine hematoxylin and eosin stains, but in some cases surrogate p16 immunohistochemical staining or molecular methods such as in situ hybridization or polymerase chain reaction can be utilized. Currently, there are eight tumor invasive variants associated with HPV, as follows: basaloid, warty, warty-basaloid, papillary basaloid, clear cell, medullary, lymphoepithelioma-like, and giant condylomas with malignant transformation. Conclusion: This review presents and describes the heterogeneous clinical, morphological, and genotypic features of the HPV-related subtypes of invasive and non-invasive penile neoplasia.

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.

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.

A comparative study of AJCC and the modified staging system in pT2/pT3 penile squamous cell carcinoma - a validation on an external data set.

AIMS: The recent changes in the American Joint Commission on Cancer, 8th edition (AJCC-8E) pT2 and pT3 tumour definitions for penile cancer need robust validation studies. A recent study redefined and modified the pT2 and pT3 stages incorporating the histopathological variables (tumour grade, lymphovascular invasion, perineural invasion) similar to that used in the current AJCC-8E pT1 stage tumour subclassification. In this study, we validate and compare this proposed staging with the AJCC staging systems on an external data set. METHODS AND RESULTS: The data set from a previously published study was obtained. pT2 and pT3 stages were reconstructed as per AJCC 7th edition (AJCC-7E), AJCC-8E and the proposed staging. The staging systems were correlated with nodal metastasis, disease-free survival (DFS), cancer-specific survival (CSS) and overall survival (OS). All systems were compared using receiver operating characteristic (ROC) curves. A total of 281 cases formed the study cohort. AJCC-8E (P = 0.031) and the proposed staging (P = 0.003) correlated with nodal metastasis on adjusted analysis, the latter with a better strength of association (AJCC-8E, γ = -0.471; proposed, γ = -0.625). On adjusted analysis, all the staging systems had a significant correlation with DFS, while only AJCC-8E and the proposed staging correlated with CSS and OS. On ROC curve analysis, the proposed staging had the highest area under the curve and was the only staging system to statistically correlate with all the outcome variables. CONCLUSIONS: The proposed staging for pT2/pT3 tumour stages in penile cancer may improve the prognostic and predictive ability.

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.

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.

[Molecular pathology of urogenital tumors : Recommendations from the 2019 International Society of Urological Pathology (ISUP) Consensus Conference]. / Molekularpathologie bei urologischen Tumoren : Empfehlungen der Konsenskonferenz der Internationalen Gesellschaft für Uropathologie (ISUP) 2019.

Comprehensive understanding of molecular principles in cancer and the diversification of oncological therapy promise individual therapeutic concepts, which have not yet found their way into urogenital cancer therapy. In March 2019 the International Society of Urogenital Pathology (ISUP) therefore held a consensus conference on recommendations for molecular diagnostics of genitourinary tumors, which were published in five separate manuscripts and are summarized in this article.In preparation for the conference, a comprehensive survey of current practices for molecular testing of urogenital tumors was carried out by members of the ISUP. At the conference, the results and the corresponding background information were presented by five working groups and recommendations for action for diagnostics were developed. An agreement between 66% of the conference participants was defined as consensus.

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.

Report From the International Society of Urological Pathology (ISUP) Consultation Conference on Molecular Pathology of Urogenital Cancers V: Recommendations on the Use of Immunohistochemical and Molecular Biomarkers in Penile Cancer.

Penile cancer and its precursor lesions are morphologically and clinically heterogenous and they can be further characterized by immunohistochemical (IHC) and molecular genetic analyses. According to the current World Health Organization (WHO) classification, penile intraepithelial neoplasia (PeIN) and invasive penile carcinomas can be grouped into human papillomavirus (HPV)-related and non-HPV-related neoplasms. This distinction is clinically relevant for etiological and prognostic reasons. To gain insight into the current use of molecular testing and IHC in their diagnostics, a survey was held among the membership of the International Society of Urological Pathology (ISUP). About 250 pathologists from 51 countries answered the survey on the practice and use of IHC/molecular technique as aids in the diagnosis of penile squamous neoplasia. More than half (60%) of the respondents worked at an academic hospital. The questions focused on condylomas, precancerous squamous lesions, and squamous cell carcinoma (SCC). About 35% to 45% of the pathologists considered the use of IHC or molecular tests of value in the pathologic evaluation of precancerous and invasive neoplasms. The vast majority of the respondents do not use IHC for the diagnosis and subtyping of condylomas. There is emerging evidence that some condylomas may participate in the penile carcinogenesis process, especially the high-risk HPV-related atypical condylomas. We recommend the use of p16 in such cases. For most PeIN cases, about half of the responding pathologists make the diagnosis on hematoxylin and eosin slides only. For their subtyping, 50% to 55% of the pathologists use IHC in warty or basaloid PeINs and 40% in differentiated PeIN. To separate HPV-related PeIN from non-HPV-related PeIN, 80% reported using p16 and 20% Ki-67. On the basis of literature review and our practice, the ISUP working group recommends the use of Ki-67 to separate non-HPV-differentiated PeIN from squamous hyperplasia and the use of p16 to distinguish the pleomorphic variant of differentiated PeIN from HPV-related PeIN. With respect to SCCs, according to the survey, immunostaining is only applied in 15% of conventional invasive SCCs, the majority being diagnosed by hematoxylin and eosin. To separate HPV and non-HPV tumors, most (80%) would use p16 and 25% would use p53. For subtype classification, they consider IHC necessary to identify verrucous, papillary, warty, warty-basaloid, and basaloid carcinomas. p16 is used as a surrogate of polymerase chain reaction for the identification of high-risk HPV. We recommend the use of p16 immunostain in cases where the tumoral histologic features of the SCCs are not classical for HPV-related neoplasms, especially in poorly differentiated tumors. Because the majority of these neoplasms harbor high-risk HPV (HPV16), identifying the presence of the virus is rather more important than documenting its specific genotype.

Topographical Evaluation of Penile Lichen Sclerosus Reveals a Lymphocytic Depleted Variant, Preferentially Associated With Neoplasia: A Report of 200 Cases.

Since the seminal study of Hart and Helwig in 1975, there are few detailed pathological studies of lichen sclerosus (LS). The aims of this study were to provide a detailed histopathological description of penile LS, as well as to explore its relationship with penile intraepithelial neoplasia (PeIN) or invasive carcinoma. We evaluated 200 patients and designed a topographical approach for the histological evaluation focusing in alterations of the following anatomical layers: squamous epithelium, lamina propria, dartos, and corpus spongiosum. We documented the quantity and topographical location of stromal lymphocytes. The prevalent lesions found were epithelial hyperplasia, atrophy, PeIN, basal cell vacuolization, lamina propria sclerosis, and variable patterns of lymphocytic infiltration. Various unique patterns of stromal sclerosis were described: perivascular, globular, linear, and solid fibrosis/hyalinization; any of them were found to be diagnostic for LS. The variation in the topography and density of lymphocytes was determinant for the identification of LS morphological variants: lichenoid, band-like, lymphocytic depleted, and mixed. A major finding was the identification of the variant designated as lymphocytic depleted LS, which we considered as the morphological prototype of LS associated with penile neoplasia. The detailed description of this complex lesion presented in this study may help pathologists in practice to identify and better define LS. The identification of the special variants suggests a role of the stromal lymphocytes in the process of carcinogenesis. Confirmation of the observations with more studies is necessary to determine the significance of these findings.

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 p16INK4a 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.

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.