Anatomic levels: important landmarks in penectomy specimens: a detailed anatomic and histologic study based on examination of 44 cases

Immunohistological study of the density and distribution of human penile neural tissue: gradient hypothesis

Immunohistological patterns of density and distribution of neural tissue in the human penis, including the prepuce, are not fully characterized, and effects of circumcision (partial or total removal of the penile prepuce) on penile sexual sensation are controversial. This study analyzed extra- and intracavernosal innervation patterns on the main penile axes using formalin-fixed, paraffin-embedded human adult and fetal penile tissues, single- and double-staining immunohistochemistry and a variety of neural and non-neural markers, with a special emphasis on the prepuce and potential sexual effects of circumcision. Immunohistochemical profiles of neural structures were determined and the most detailed immunohistological characterizations to date of preputial nerve supply are provided. The penile prepuce has a highly organized, dense, afferent innervation pattern that is manifest early in fetal development. Autonomically, it receives noradrenergic sympathetic and nitrergic parasympathetic innervation. Cholinergic nerves are also present. We observed cutaneous and subcutaneous neural density distribution biases across our specimens towards the ventral prepuce, including a region corresponding in the adult anatomical position (penis erect) to the distal third of the ventral penile aspect. We also describe a concept of innervation gradients across the longitudinal and transverse penile axes. Results are discussed in relation to the specialized literature. An argument is made that neuroanatomic substrates underlying unusual permanent penile sensory disturbances post-circumcision are related to heightened neural levels in the distal third of the ventral penile aspect, which could potentially be compromised by deep incisions during circumcision.

Epithelial Lesions Associated with Invasive Penile Squamous Cell Carcinoma: A Pathologic Study of 288 Cases

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

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.

Whole-mount evaluation of penectomies for penile cancer: feasibility, cost and comparison to routine sectioning

AIMS

Pathological staging in penectomies may be difficult due to the anatomical complexity of penile anatomy, and may be additionally challenging due to the low volume at most institutions. Our study aimed to assess the feasibility of whole-mount processing for penectomy specimens.

METHODS AND RESULTS

A 7-year retrospective search for partial or radical penectomies identified 55 specimens, which were processed routinely (n = 31) from 2006 to 2009 and whole-mounted (n = 24) from 2010 to 2012. Routine cases used more slides per case compared to whole mounts (mean 10.4 versus 7.2). Recuts occurred more often in routine cases (12.9% versus 0%). More routine cases had additional blocks grossed (19.4% versus 4.2%). Upon review, five discrepancies that impacted pT staging were identified in the routine group, with none in the whole-mount group. The average estimated additional cost for each whole-mount case compared to routine processing was $40.74, with an increased turnaround time of 1 day.

CONCLUSIONS

Whole-mounting is a feasible technique for penectomy that can be utilized with minimal increased cost and turnaround time, and may improve staging. Institutions in which whole-mounting is already established for other organs, such as prostate, may wish to consider utilizing this format for penectomy specimens.

C-MET is expressed in the majority of penile squamous cell carcinomas and correlates with polysomy-7 but is not associated with MET oncogene amplification, pertinent histopathologic parameters, or with cancer-specific survival

We assessed c-MET expression and oncogene amplification in a cohort enrolling 92 surgically treated penile squamous cell carcinomas (PSCCs). A tissue microarray was constructed for c-MET immunohistochemistry (IHC) and chromogenic silver in situ hybridization (SISH). Two independent pathologists evaluated IHC by employing the breast cancer scoring rules, and scored the presence of MET oncogene amplification and/or polysomy-7. Eighty study cases (87%) showed c-MET expression. No study case had MET oncogene amplification, but 42 patients (45.7%) had polysomy-7. Polysomy-7 showed a significant positive correlation with c-MET expression (ρ=0.323, p=0.002). Neither c-MET expression nor polysomy-7 was associated with histopathologic parameters or with cancer-specific survival (median post-surgical follow-up 32 months). Our data suggest that the majority of PSCCs exhibit c-MET expression which is not associated with oncogene amplification, but might be attributable to polysomy-7. Further studies should investigate the expression and activation of downstream molecules functionally involved in c-MET pathway signaling, and clarify the so far unresolved role of c-MET inhibitors as potential targeted therapies in PSCCs with metastatic dissemination.

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.

Penile cancer: clinical presentation, diagnosis, and staging

Penile cancer is an uncommon malignancy in developed countries, with an estimated 1290 new cases of invasive penile cancer and 290 deaths among men in the United States in 2009, but is much more common in the developing countries of Asia, Africa, and South America. This disease can result in loss of function, disfigurement, and death. Thus, recognizing penile cancer early in the clinical setting and accurately diagnosing the patients is critical. Because the management and prognosis varies by the extent of local disease, lymph node status, and other factors, accurate staging of penile cancer is of utmost importance. This article focuses on the presentation, diagnosis, and staging of invasive squamous cell carcinoma of the penis. The authors highlight the recent changes to the American Joint Committee on Cancer's staging system for penile carcinoma and discuss other prognostic factors and predictive models.

Comparison of morphologic features and outcome of resected recurrent and nonrecurrent squamous cell carcinoma of the penis: a study of 81 cases

Penile squamous cell carcinoma (SCC) is considered a loco-regional disease with a fairly predictable pattern of progression. Widespread dissemination occurs in at least one-third of the patients. Local recurrence (defined as the presence of tumor after a primary treatment affecting any remainder tissue, including skin, erectile corpora, or urethra) present in up to 30% of the patients increases the risk of regional inguinal and pelvic lymph nodes metastases. The aim of this study was to identify adverse pathologic prognostic factors in patients with recurrent tumors. Clinicopathologic features of 81 surgically treated patients (25 with recurrent and 56 with nonrecurrent SCC) were evaluated; 56 patients (19 with recurrent and 37 with nonrecurrent tumors) additionally received groin dissections. Follow-up (2 to 372 mo, mean of 71 mo) was obtained in all patients. Comparison of recurrent tumors at the time of the primary diagnosis and of recurrence showed that histologic subtype and grade were identical in 76% of the cases and converted to a higher grade tumor in 24% of the cases, especially, in patients treated with local excisions and circumcisions. Most of the recurrences (67%) seemed at or before 12 months. Comparison of recurrent and nonrecurrent tumors showed that high grade tumors (basaloid and sarcomatoid) tended to be significantly associated with recurrent tumors, whereas low grade variants (papillary, warty and verrucous) were more frequent in the nonrecurrent group; recurrent tumors invaded into deeper anatomic levels than nonrecurrent tumors. The incidence of inguinal lymph node metastasis was higher in recurrent tumors (79% vs. 49%, P=0.0272). Cancer-specific survival was of 46% versus 76% at 3 years of follow-up in recurrent and nonrecurrent tumors, respectively. Patients with recurrent tumors had a median survival of 2.9 years; no major changes in survival were noted after 3 years of follow-up. Mortality was higher in the recurrent group (56% vs. 29%, P=0.0188); 80% of patients with high-grade tumors (basaloid, sarcomatoid, and high grade usual or hybrid verrucous SCCs) died from penile cancer. Mortality in patients with usual SCC was higher in the recurrent group, but similar in basaloid and sarcomatoid SCCs. After 3 years there was no survival difference in patients with low-grade recurrent tumors; however, in the high grade recurrent group there was a progressive and gradual decrease in survival from 2 to 10 years (median survival of 2.5 y). In summary, histologic subtypes and grades of SCCs were similar in the majority of original and recurrent carcinomas. Inguinal metastasis and mortality were higher in recurrent than in nonrecurrent carcinomas. Basaloid, sarcomatoid, and mixed usual-verrucous variants and invasion of corpora cavernosa or preputial skin were significant adverse prognostic factors of recurrent carcinomas. Local excision and partial penectomy were not adequate procedures for sarcomatoid and basaloid penile carcinomas. Carcinomas of foreskin had a better prognosis. Conversion from low to high-grade carcinoma was related to significant mortality. The identification of the adverse prognostic factors found in this study should be the base for an aggressive initial therapy to prevent recurrence in a subset of penile cancers. Re-excision of the recurrent tumor permitted the control of the disease only in one-third of the patients.

Penile squamous cell carcinoma clinicopathological features, nodal metastasis and outcome in 333 cases

PURPOSE

We evaluated clinicopathological features and outcomes in patients with penile squamous cell carcinoma.

MATERIALS AND METHODS

We studied 333 patients with homogeneous surgical treatment, including circumcision in 4, local excision in 2, partial penectomy in 194 and total penectomy in 133. Of the patients 153 also underwent bilateral groin dissection. Followup was 8 to 453 months (average 100).

RESULTS

The usual type of squamous cell carcinoma was noted in 65% of cases. Higher histological grade, deeper anatomical infiltration, and vascular and perineural invasion were common findings in sarcomatoid, basaloid and adenosquamous carcinoma cases, correlating with a higher rate of nodal metastasis and mortality. These features were unusual in verrucous, papillary and warty carcinoma cases. Recurrence in 22% of cases was common for the sarcomatoid, basaloid and adenosquamous types but was not noted for verrucous carcinoma. Locoregional relapse was more common in cases of usual, mixed, papillary and warty carcinoma, and systemic relapse was typical in sarcomatoid and basaloid carcinoma cases. The overall metastasis rate was 24% and the 10-year survival rate was 82%. The highest mortality rate was observed within the first 3 years of followup. High grade tumors were more common in penectomy cases and carcinoma exclusive of the foreskin had a better prognosis. The nodal metastasis risk groups were low--verrucous, papillary and warty, intermediate--usual and mixed, and high risk--sarcomatoid, basaloid and adenosquamous. Mortality risk groups were low--mixed, papillary and warty, intermediate--usual and basaloid, and high risk--sarcomatoid.

CONCLUSIONS

These data should help clinicians to design therapeutic strategies and followup protocols.

Autopsy Findings in 14 Patients With Penile Squamous Cell Carcinoma

The aim of this study was to describe pathologic features found at autopsy of 14 patients with penile cancer. Nine patients died from disseminated disease; 5 of them presented local/regional recurrences. Five patients died from other causes, 2 of them postoperatively. Local recurrence sites were corpus cavernosum, Buck’s fascia and urethra, regional skin, and prostate. Metastatic sites were lymph nodes (9 cases), liver (7 cases), lungs (6 cases), heart (5 cases), adrenals, bone and skin (3 cases each), thyroid and brain (2 cases each), and pancreas, spleen, and pleura (1 case each). Patients with heart metastasis had arrhythmias. Patients who died and who did not die from penile cancer had different profiles: low-grade superficial tumors with usual and warty subtypes versus high-grade deeply invasive basaloid or hybrid verrucous/sarcomatoid carcinomas. A natural history model for penile cancer routes of spread is proposed: local intrapeneal, regional and systemic nodes, regional skin, liver, lungs, heart, and other multiple sites.

Benign Diseases and Neoplasms of the Penis

This article provides comprehensive review of benign diseases and neoplastic conditions of the penis. It describes and provides representative images of clinical, key pathologic features and ancillary techniques to aid in differential diagnoses. It examines these diseases from the epidemiologic standpoint, looks at environmental and genetic factors, and outlines the new histologic entities for penile neoplasms with distinct outcomes and clinical behavior that have been proposed in recent years.

Histologic grade and perineural invasion are more important than tumor thickness as predictor of nodal metastasis in penile squamous cell carcinoma invading 5 to 10 mm

Penile squamous cell carcinomas (SCCs) invading to a depth inferior to 5 mm usually have very low risk for regional metastasis, whereas tumors thicker than 10 mm have a high metastatic potential. A significant number of squamous cell carcinomas, however, belong to an intermediate category (5 to 10 mm in thickness) in which the incidence of regional lymph node metastasis is very difficult to predict. Consequently, a frequent clinical dilemma is whether to perform or not inguinal dissection in this group of lesions. The objective of this study was to evaluate multiple risk factors for regional metastasis in tumors 5 to 10-mm thick. One hundred thirty-four partial penectomies with invasive carcinomas 5 to 10-mm thick, all of which with corresponding inguinal lymph node dissection, were evaluated. Factors evaluated were--patient's age, anatomic site, histologic grade, tumor thickness, anatomic levels of invasion, and vascular and perineural invasion. Grades were classified as 1, well; 2, moderately; and 3, poorly differentiated. To evaluate independent significance of various prognostic factors, a logistic regression analysis was performed, and a nomogram was prepared to evaluate metastatic risk according to histologic grade and perineural invasion. Groin metastasis was found in 66 of 134 patients (49%). High histologic grade and perineural invasion were statistically significant pathologic factors associated with groin metastasis. Nodal metastases were found in 2 of 25 grade 1 (8%), 24 of 46 grade 2 (52%), and 40 of 63 grade 3 carcinomas (63%) (P value 0.0001). Of 48 patients with perineural invasion, metastasis was found in 33 cases (69%) (P value 0.001). The average tumor thickness, anatomic level of invasion, and presence of vascular invasion were not statistically significantly different in metastasizing and nonmetastasizing neoplasms. Fifty percent of tumors invading 5 to 10 mm were not associated with metastasis and may be spared a nodal dissection. In this subset of patients, high histologic grade and perineural invasion were significant and useful risk factors associated with regional metastasis. The probability of inguinal node metastasis in patients with grade 1 tumors without perineural invasion is almost nonexistent whereas for high-grade tumors associated with perineural invasion is near 80%.

The expression of metaloproteinases-2 and -9 is different according to the patterns of growth and invasion in squamous cell carcinoma of the penis

Squamous cell carcinoma (SCC) of the penis is characterized by different patterns of growth and local invasion. The matrix metalloproteinases (MMPs) is a family of proteolytic enzymes that are involved in the degradation of extracellular matrix to allow the migration of tumor cells. The present study examined whether the expression of MMP-2 and -9 is correlated with the patterns of tumor growth and invasion in penile SCC. The expression of MMP-2 and -9 was examined immunohistochemically in samples of 115 patients. The cases were divided in three groups according to the patterns of growth and invasion: group 1, exophytic growth and pushing pattern of invasion; group 2, endophytic growth and invasion in large sheets of cells; and group 3, endophytic growth and invasion in small group or isolated cells. Tumors with MMP-2 and -9 overexpression are deeply invasive and present an invasion pattern of small groups of cells. Also, expression of MMP-2 changed from membrane to cytoplasm in invasive tumors, maybe representing activation of MMP-2. These findings allow us to conclude that the less differentiated tumors, which are more invasive and with a pattern of invasion in small group of cells, are associated with the overexpression of MMPs.

Penile cancer

Penile cancer, while relatively rare in the western world, remains a disease with severe morbidity and mortality, not to mention significant psychological ramifications. Furthermore, the disease is observed with dramatically increased incidence in other parts of the world. A review of the literature has shown that the overwhelming majority of penile cancers are in situ or invasive squamous cell carcinomas, including a well-differentiated variant, verrucous carcinoma. Important predisposing factors are lack of circumcision, human papillomavirus infections, and penile lichen sclerosus, although other factors have occasionally been reported as well. Prevention, careful monitoring of patients at risk, and early diagnosis are essential to reduce the incidence of penile carcinoma and to provide a definitive cure. Public health measures, such as prophylactic use of circumcision, have proved successful but are controversial. Also, no standard therapeutic guidelines as to the best treatment strategy according to different stages, including efficacy of conservative nonsurgical modalities and indications for lymph nodal dissection, are available so far. It is common opinion that penile cancer is an emerging problem that deserves further investigations, and physicians, especially dermatologists, should be aware of this issue.

LEARNING OBJECTIVE

At the completion of this learning activity, participants should be familiar with penile carcinoma, its risk factors, its clinical and histologic presentation, and the treatments currently available for its management.

Epithelial abnormalities and precancerous lesions of anterior urethra in patients with penile carcinoma: a report of 89 cases

Urethral and penile tissues and their neoplasms are considered anatomically and pathogenetically different. Since we observed urethral dysplastic lesions and some similarities between noninvasive and invasive lesions of the anterior urethra and glans, we designed this study to document epithelial urethral abnormalities in patients with penile squamous cell carcinoma. We examined urethral epithelia from 170 penectomies with invasive squamous cell carcinoma finding a variety of primary epithelial abnormalities in 89 cases (52%) and secondary invasion of penile carcinoma to urethra in 42 cases (25%). Patients' average age was 68 years. Primary tumors measured 4 cm in average diameter and the majority were squamous cell carcinoma of the usual (67%) or verrucous type (15%). Primary epithelial abnormalities found were squamous intraepithelial lesions, metaplasias and microglandular hyperplasias. Urethral squamous intraepithelial lesions of high grade was found in six patients and of low grade in eight cases. Squamous metaplasia, seen in 69 cases, was the most frequent finding. Metaplasias were classified as nonkeratinizing and keratinizing. Nonkeratinizing metaplasias (57 cases) were variegated in morphology: simplex (26 cases), hyperplastic (12 cases), clear cell (11 cases) and spindle (8 cases). Keratinizing metaplasias (12 cases) showed hyperkeratosis and were more frequently associated with verrucous than nonverrucous penile squamous cell carcinoma. Microglandular hyperplasia was present in eight cases. Lichen sclerosus was associated with simplex squamous metaplasia in four cases. Despite the large size of the primary tumors, direct urethral invasion by penile carcinoma was present in only 25% of the cases. The presence of precancerous lesions in urethra of patients with penile carcinoma indicates urethral participation in the pathogenesis of penile cancer. Simplex squamous metaplasia is a common finding probably related to chronic inflammation. Keratinizing and hyperplastic squamous metaplasias may be important in the pathogenesis of special types of penile carcinomas such as verrucous carcinoma.

Limitations in the interpretation of biopsies in patients with penile squamous cell carcinoma

Surgeons often perform small or superficial penile biopsies that are difficult to classify definitely with regard to a benign or malignant nature, and if malignant, cannot always be accurately subclassified. Staging and therapeutic decisions rely on the identification, in these materials, of pathologic parameters related to prognosis. In this study, we evaluated the accuracy and completeness of pathologic information obtained from biopsies of 57 consecutive patients with squamous cell carcinoma (SSC) of the penis, and compared it with the information obtained from penectomies. Diagnostic accuracy was determined by recording discordances of critical factors in biopsies and penectomies. The evaluated parameters were as follows: cancer diagnosis, histologic type, tumor grade, depth of invasion (anatomical levels), and vascular invasion. Histologic subtypes of SCC were the following: usual 37, verruciform 11, mixed 7, pseudohyperplastic 1, and sarcomatoid 1. Grades were 1, 2, and 3 (well, moderately and poorly differentiated). Levels of invasion were lamina propria, corpus spongiosum, and corpus cavernosum in the glans; and lamina propria, dartos, and skin in the foreskin. In 2 patients with well-differentiated tumors a diagnosis of cancer could not be established in biopsy material. In 17 cases (30%) there was a biopsy-penectomy discordance of histologic types, especially of verruciform and mixed carcinomas. Biopsies failed to identify the correct histologic grade in 30% of the cases. A higher grade was usually identified in penectomy specimens. Because biopsies were superficial, the deepest point of invasion could not be determined in 91% of the cases. Vascular invasion was identified in biopsies in only 1 of 8 patients. In summary, biopsies were useful for cancer diagnosis except in 2 differentiated variants of penile squamous cell carcinoma. However, important pathologic parameters related to prognosis were missed on biopsy materials, and they were more accurately evaluated in penectomy specimens. We conclude that clinical and pathologic staging of penile cancer, at least in our material, cannot depend on biopsy information alone. Data from biopsies may be insufficient to make a decision whether to perform a groin dissection, or for prognostic evaluation in those patients in whom other treatment modalities (such as radiotherapy or chemotherapy) are being considered.

Pseudohyperplastic Squamous Cell Carcinoma of the Penis Associated With Lichen Sclerosus. An Extremely Well-differentiated, Nonverruciform Neoplasm That Preferentially Affects the Foreskin and Is Frequently Misdiagnosed

We present 10 cases of well-differentiated, squamous cell carcinoma of the penis with pseudohyperplastic features. At presentation, the median age was 69 years. Seven of the tumors were multicentric, and the majority preferentially involved the foreskin inner mucosal surface. Grossly the tumors were typically flat or slightly elevated, white and granular, and measured approximately 2 cm. Characteristic histologic features included keratinizing nests of squamous cells with minimal atypia surrounded by a reactive fibrous stroma. In biopsies or individual areas of resected specimens, the differential diagnosis with pseudoepitheliomatous hyperplasia was difficult but when samples of adequate size were available, obvious evidence of infiltration was present. The adjacent squamous epithelium typically showed changes that are known to be associated with squamous cell carcinoma ranging from squamous hyperplasia to low-grade, and in a few cases high-grade, squamous intraepithelial lesions. Well-developed lichen sclerosus was seen in all cases. Patients were treated by circumcision or partial penectomy. With the exception of 1 patient who developed a glans recurrence 2 years after initial circumcision, follow-up after the initial surgical procedure has been uneventful. The majority of penile carcinomas with the high degree of differentiation seen in these cases are in the category of the verruciform tumors, either the verrucous or papillary carcinoma, not otherwise-specified subtypes. Experience with the cases reported in this series indicates that a subset of nonverruciform, often multicentric, tumors with a high degree of differentiation and pseudohyperplastic features occur and preferentially involve the foreskin. Because it was present in all cases, lichen sclerosus may play a precancerous role.

Positive Resection Margins in Partial Penectomies

Recurrence in patients with penile carcinoma occurs in about one third of cases, usually due to insufficient surgery or positive resection margins. An evaluation of surgical resection margins in penectomy specimens was performed to determine precise anatomic sites of tumor involvement, hoping to advance knowledge concerning the local routes of spread of penile carcinomas. A pathologic study of 80 partial penectomies revealed 14 positive margins. Margins were examined after their separation from the main specimen as follows: 1) proximal urethra and surrounding tissues consisting of urethral epithelium with Litree glands, lamina propria, corpus spongiosum, and penile fascia (periurethral cylinder); 2) proximal shaft with corresponding corpora cavernosa separated and surrounded by the tunica albuginea and penile fascia; and 3) skin of shaft with underlying corporal dartos. In 9 patients, only one site was involved by carcinoma, and in 5 there were multiple contiguous sites (for a total of 20 anatomic sites). The distribution of the various sites involved by carcinoma was as follows: urethral epithelium, 4 cases (2 in situ and 2 invasive carcinomas including intraluminal spread); lamina propria, 5 cases; corpus spongiosum, 3 cases; penile fascia, 6 cases; and corpora cavernosa and skin, 1 case each. One of the in situ lesions was discontinuous with the main glans tumor, and the other one was continuous with it. The penile fascia was the most commonly involved site followed by the urethral lamina propria and epithelium. Dissemination to outer skin, corpora cavernosa, and corpus spongiosum was less frequent. The highly vascularized and innervated loose connective tissue of the penile fascia appears to facilitate tumor spread. The urethra is either a pathway for in situ tumor progression from glans to urethra or part of a field prone to malignant transformation. The infrequent involvement of corpora cavernosa is probably due to the tunica albuginea acting as a barrier preventing tumor spread. Based on these observations and the examination of hundreds of penectomy specimens, we are proposing five probable routes of local spread for penile cancer: 1) horizontal and superficially spreading from one epithelial mucosal compartment (glans, coronal sulcus, and foreskin) to the other; 2) following the penile fascia; 3) through spaces created by feeding vessels in the tunica albuginea; 4) vertical spreading involving step-by-step different penile anatomic compartments; and 5) along the urethral epithelium.

Invasive Penile Carcinoma: A Review

BACKGROUND

Penile carcinoma is an invasive epithelial tumor that may arise from penile skin or mucosa.

OBJECTIVE

To review the pathogenesis and the clinical and histopathologic features of invasive penile carcinomas, with emphasis on current guidelines for their diagnosis and treatment.

METHODS

Information available from the authors' clinical experience, review articles, case reports, clinical trials, and in vitro research studies identified from a computerized literature search on MEDLINE database and from Meetings' Abstract Books, including those from non-English literature, was considered.

RESULTS

Penile cancer may develop de novo or in association with underlying factors. Conditions predisposing to the development of penile cancer are delineated. The diagnosis should be suspected by clinical findings and must be confirmed histologically. Imaging techniques may be useful for staging and planning therapy. Therapeutic options include excisional surgery, laser destruction, cryosurgery, radiotherapy, immunotherapy, and chemotherapy.

CONCLUSIONS

Although there are no current guidelines for the treatment of penile carcinoma, surgical ablation probably represents the best option, as conservative treatments still deserve cautious evaluation because of the relatively small number of treated patients and the lack of good-quality comparative data. Regarding indications for lymph nodal dissection in patients showing no inguinal node enlargement, sentinel node mapping with targeted lymph node dissection is recommended for those with deeply invasive, high-grade tumors, whereas a watchful waiting may be advised for those with superficially invasive, low-grade tumors.