Role of human papillomavirus in squamous cell metaplasia-dysplasia-carcinoma of the rectum

Primary colorectal squamous cell carcinoma (SCC) and squamous dysplasia are uncommon and little is known about their pathogenesis. Most have been reported in association with ulcerative colitis and other chronic disease states. Although cervical and anal SCC have been strongly linked to human papillomavirus (HPV) infection, the role of HPV in rectal squamous carcinoma has not been well-examined. We evaluated 3 cases of primary rectal SCC for the presence of high-risk HPV by immunohistochemistry for p16(INK4A), in situ hybridization, and polymerase chain reaction. HPV type 16 was detected by polymerase chain reaction in all cases. In addition, all cases exhibited diffuse strong reactivity for p16(INK4A) and punctate nuclear staining by Ventana HPVIII in situ hybridization. The presence of HPV 16 in all three cases suggests that high-risk HPV infection is a risk factor for rectal SCC, particularly in patients with underlying chronic inflammatory disease processes or altered immune status. Further studies are warranted to determine if SCC occurring more proximal in the colon are also HPV-dependent or occur via another, HPV-independent pathway.     

Human papillomaviruses 6/11, 16/18 and 31/33/51 are not associated with squamous cell carcinoma of the urinary bladder

OBJECTIVE: To assess high-risk human papillomavirus (HPV), mainly HPV type 16, 18, 31 and 33 (an important aetiological factor in squamous cell carcinoma, SCC, of the anogenital region) in SCC of the urinary bladder. MATERIAL AND METHODS: Sixteen SCC from the urinary bladder were evaluated using non-isotopic in situ hybridization with a sensitive detection system for the presence of high-risk HPV 16/18, or 31/33/51, and for HPV6/11, a low-risk type commonly found in condylomata. Previously published studies were also reviewed and assessed. RESULTS: No high-risk HPV was found in any of the SCC of the bladder evaluated. Previous reports identified nine HPV-positive SCC of a total of 105, including the present series. In four of these positive cases, HPV types were found that are considered a high risk in anogenital carcinomas. CONCLUSION: From the present and previous results, we conclude that HPV has no major role in the pathogenesis of SCC of the urinary bladder.     

Tumor cell anaplasia and multinucleation are predictors of disease recurrence in oropharyngeal squamous cell carcinoma, including among just the human papillomavirus-related cancers

Oropharyngeal squamous cell carcinoma (SCC) is frequently related to high risk human papillomavirus. This tumor expresses p16, frequently has a nonkeratinizing morphology, and has improved outcomes. Despite having a good prognosis, tumors can have focal or diffuse nuclear anaplasia or multinucleation, the significance of which is unknown. From a database of 270 oropharyngeal SCCs with known histologic typing (using our established system) and p16 immunohistochemistry, all surgically resected cases (149) were reviewed. Anaplasia was defined as any × 40 field with ≥ 3 tumor nuclei with diameters ≥ 5 lymphocyte nuclei (~25 μm), and multinucleation was defined as any × 40 field with ≥ 3 tumor cells with multiple nuclei. p16 was positive in 128 cases (85.9%), 64 cases (43.0%) showed anaplasia, and 71 (47.7%) showed multinucleation. Anaplasia and multinucleation were highly related (P<0.001), and both also correlated with histologic type (P<0.001 and P=0.01, respectively), p16 status (P=0.09 and 0.03, respectively), and partially with nodal extracapsular extension. There was no correlation with any of the other variables. In univariate analysis, cases showing anaplasia or multinucleation had worse overall, disease-specific, and disease-free survival (P<0.006 for all). Higher T-stage, keratinizing histologic type, extracapsular extension, and smoking also all correlated with worse survival. In multivariate analysis, anaplasia and multinucleation both predicted worse disease-specific survival (hazard ratio 9.9, P=0.04; and hazard ratio 11.9, P=0.02, respectively) independent of the other variables. In summary, among surgically resectable oropharyngeal SCC (including among just the p16-positive cohort), tumor cell anaplasia and multinucleation independently correlated with disease recurrence and poorer survival.     

HPV-Related Nonkeratinizing Squamous Cell Carcinoma of the Oropharynx: Utility of Microscopic Features in Predicting Patient Outcome

Human papilloma virus (HPV) is an etiologic agent in a subset of oropharyngeal squamous cell carcinomas (SCCs). The aim of this study was to sub-classify SCC of the oropharynx based upon histologic features into nonkeratinizing (NK) SCC, keratinizing (K) SCC, and hybrid SCC, and determine the frequency of HPV and patient survival in each group. Patients with oropharyngeal SCC with a minimum of 2 years of clinical follow-up were identified from radiation oncology databases from 1997 to 2004. All patients received either up front surgery with postoperative radiation or definitive radiation based therapy. In situ hybridization (ISH) for high-risk HPV subtypes and immunohistochemistry for p16, a protein frequently up-regulated in HPV-associated carcinomas, were performed. Overall and disease-specific survival were assessed. Of 118 cases, 46.6% were NK SCC, 24.6% K SCC and 28.8% hybrid SCC. NK SCC occurred in slightly younger patients that were more often male. It more frequently presented with lymph node metastases and was surgically resected compared to K SCC. NK SCC was significantly more likely to be HPV and p16 positive than KSCC (P < 0.001) and to have better overall and disease-specific survival (P = 0.0002; P = 0.0142, respectively). Hybrid SCC was also more likely than K SCC to be HPV and p16 positive (P = 0.003; P = 0.002, respectively) and to have better overall survival (P = 0.0105). Sub-classification of oropharyngeal SCC by histologic type provides useful clinical information. NK SCC histology strongly predicts HPV-association and better patient survival compared to K SCC. Hybrid SCC appears to have an intermediate frequency of HPV-association and patient survival.     

Anal cloacogenic and squamous carcinomas. Comparative histologic analysis using in situ hybridization for human papillomavirus DNA

In order to evaluate the morphologic and possible etiologic distinctions between anal cloacogenic and squamous carcinomas, we performed histologic examination and in situ hybridization for human papillomavirus (HPV) DNA on anal canal and anal verge carcinomas from 37 patients. Twenty-one neoplasms were invasive or in situ squamous carcinomas, 14 were invasive cloacogenic carcinomas, and two were unclassified. In situ hybridization was positive for HPV types 16/18 in 12 cases and for types 6/11 in two cases of anal squamous carcinoma (67% HPV positivity overall). All 14 cases classified as anal cloacogenic carcinoma were negative for HPV DNA by this technique. One of the two unclassified carcinomas was positive for type 16/18 DNA. We conclude that anal cloacogenic and squamous carcinomas are histologically similar but distinct neoplasms. Differential expression of HPV DNA in these lesions may be a manifestation of separate mechanisms of pathogenesis, or it may be due to varying degrees of tumor cell differentiation.     

Eosinophilic dysplasia of the cervix: a newly recognized variant of cervical squamous intraepithelial neoplasia

A proportion of cervical squamous intraepithelial lesions encountered in surgical pathology practice contain both metaplastic features and some degree of atypia [so-called eosinophilic dysplasia (ED)] that defy classification according to established criteria. To elucidate the nature of these lesions, we compared 44 cases of ED to 20 classic high-grade squamous intraepithelial lesions (HSILs) and 10 squamous metaplasias using a panel of biomarkers and human papillomavirus (HPV) testing. EDs were defined as 1) lack of normal maturation; 2) relatively abundant eosinophilic cytoplasm and distinct cell borders compared with conventional HSIL; 3) mildly to moderately increased nuclear to cytoplasmic ratio; and 4) focal dysplastic nuclei showing nuclear enlargement, hyperchromasia, variable nuclear membrane irregularities, and appreciable nucleoli. Expression of p16 (p16), MIB-1 (Ki-67) labeling index, and HPV DNA detection and typing were performed on each case. The majority of EDs showed more than three atypical cells in an entire lesion but lack of apparent features of HSIL. It was common to find neighboring cervical squamous metaplasia and/or conventional SILs (either HSIL or low-grade squamous intraepithelial lesion [LSIL]). Among the 44 cases, 18 (45%) ED lesions were found to be associated with HSIL, 15 (34%) with LSIL or condylomatous lesions, and 13 (30%) EDs were seen without any SILs in the entire specimens. Area of benign squamous metaplasia was found in all ED cases. High levels of p16 and MIB-1 expression were seen in 41 (93%) of 44 ED cases with degrees of immunoreactivity closely resembling those seen with HSIL. Of 16 EDs tested, 13 (81%) were positive for HPV DNAs. Among 10 HPV-positive cases subtyped, 9 (90%) cases contained intermediate- and/or high-risk HPVs and 1 case contained a novel HPV. In the follow-up of pure ED cases, the majority showed presence of dysplastic lesions of either HSIL or LSIL on either loop electric excision procedures or Papanicolaou test samples after a 6- to 10-week period. Therefore, ED represents an unrecognized and potentially clinically significant subgroup of cervical intraepithelial lesions. Based on the unique histologic appearance of ED, its association in some cases with HSIL, the overall immunohistochemical findings, frequent association of ED with intermediate- and/or high-risk HPV infection, and limited follow-up data, we believe that ED represents a variant of HSIL (CIN 2). Since ED possesses histologic features of both dysplasia and metaplasia, we speculate that it may arise from metaplastic cervical squamous epithelium that has subsequently become infected with intermediate- or high-risk HPV.     

p16 overexpression identifies HPV-positive vulvar squamous cell carcinomas

Two types of vulvar squamous cell carcinomas (VSCCs) are recognized according to their relationship to human papillomavirus (HPV). Basaloid or warty carcinomas are considered HPV-associated tumors, whereas differentiated keratinizing neoplasms are considered non-HPV-associated. Recently, immunohistochemical detection of p16 and p53 has been proposed to differentiate these 2 types of VSCCs. We conducted a histologic study with immunohistochemical evaluation of p16 and p53 and HPV detection and typing by polymerase chain reaction using 2 different sets of primers in 92 cases of VSCCs to evaluate the usefulness of immunohistochemistry in the classification of VSCCs and to describe the clinico-pathologic characteristics of both types of VSCCs. HPV was detected in 16/92 (17.4%) specimens, HPV16 being identified in 75% of positive cases. A significant number of discrepancies between histology and HPV detection were observed, with 37.5% of HPV-positive tumors being keratinizing and 9.2% of HPV-negative carcinomas showing basaloid or warty features. Diffuse positivity for p16 and p53 was observed in 100% and 6.2% of HPV-positive tumors and in 2.3% and 64.5% of HPV-negative neoplasms, respectively. The sensitivity and specificity of p16 immunostaining to detect HPV-associated carcinomas (100% and 98.7%, respectively) were better than those of histologic criteria (93.8% and 35.5%) and of p53 negative stain (62.5% and 93.4%). Vulvar intraepithelial neoplasia grade 3 of basaloid/warty type was identified in 53.8% HPV-positive tumors, including 3 keratinizing tumors. All these cases were p16 positive and p53 negative. Vulvar intraepithelial neoplasia grade 3 of differentiated type was observed in 45.6% of HPV-negative cases; 90.8% of them were positive for p53 but all were negative for p16. No differences in age, stage, or development of recurrence were observed between HPV-positive and negative tumors. In summary, the current morphologic criteria to discriminate HPV-positive and negative VSCCs have a significant overlap. Immunostaining for p16 is a reliable marker for HPV-positive VSSCs, which improves the results of histologic classification.     

Small Biopsy Specimens Reliably Indicate p16 Expression Status of Oropharyngeal Squamous Cell Carcinoma

Human papillomavirus (HPV)—related oropharyngeal squamous cell carcinoma (SCC) is associated with favorable patient survival. Tumor HPV status at primary diagnosis is critical for proper management, and p16 immunohistochemistry (IHC) has emerged as a reliable, single, surrogate marker. It is not known, however, if small biopsy specimens are completely adequate for p16 evaluation. From a database of oropharyngeal SCC for which p16 IHC and histologic typing were already performed, all patients (32) who had available in-house primary tumor biopsy specimens and also subsequent surgical resections were analyzed. p16 IHC was performed along with histologic typing into: Type 1 keratinizing SCC, Type 2 nonkeratinizing SCC with maturation, and Type 3 nonkeratinizing SCC. Staining was graded on both biopsies and resections as follows: 0 = negative; 1+ = 1–25% of tumor cells positive; 2+ = 26–50%; 3+ = 51–75%; 4+ = 76–100%. Strictly considering p16 score, perfect biopsy-resection correlation was present in 28 of 32 cases (85%), including 6/9 (67%) Type 1, 6/7 (86%) Type 2, and 16/16 (100%) Type 3 cases. Considering p16 expression binarily as 51% tumor cell staining or more (3+ or 4+) being positive and lesser amounts (0, 1+, or 2+) as being negative, there was perfect biopsy-resection correlation for all 32 cases. With p16 expression in resection specimens considered the gold standard, p16 IHC in biopsies was both 100% sensitive and specific. Our results demonstrate that p16 staining in diagnostic biopsies reliably reflects whole tumor staining results, and suggest that biopsies do not suffer from false negatives or positives.     

The distribution of low and high-risk HPV types in vulvar and vaginal intraepithelial neoplasia (VIN and VaIN)

It has been proposed that low-grade vulvar and vaginal lesions (VIN 1 and VaIN 1) are flat condylomas and should be designated as such. Moreover, their relationship to high-grade lesions (VIN 3 and VaIN 3) is unclear. Accordingly, this study was undertaken to address these issues by comparing the distribution of human papillomavirus (HPV) types in vulvar and vaginal intraepithelial lesions. We identified 33 cases of VIN 1, 34 cases of VIN 3, 17 cases of VaIN 1, and 16 cases of VaIN 3. In addition, 36 cases of low-grade squamous intraepithelial lesion (LSIL) in the cervix and 116 cases of cervical high-grade squamous intraepithelial lesion were used for comparison. Polymerase chain reaction analysis was performed using both the Roche PGMY and DDL SPF 10 systems. In cases where HPV was detected, the majority of low-grade and high-grade lesions contained a single HPV type. However, a minority of cases were found to have multiple HPV types. Of the VIN 1 cases, a low-risk virus was seen in 22 (67%), with HPV 6 or 11 accounting for 14 (42%). A high-risk virus was detected in 14 (42%) of cases of which 2 (6%) contained HPV 16. Of the VIN 3 cases, all had high-risk HPV of which 31 (91%) were found to have HPV 16. Of the VaIN 1 cases, 6 (35%) were found to have low-risk HPV types. HPV 6 or 11 were not found in these cases. High-risk virus was seen in 13 (76%) VaIN 1 cases, with 1 (6%) containing HPV 16. HPV was detected in 15 of 16 (94%) VaIN 3 lesions, all of which had high-risk types. HPV 16 was found in 8 (50%). In contrast, 2 (6%) of cervical LSIL had low-risk HPV (HPV 6 and 11), whereas 34 (94%) of LSIL cases had high-risk HPVs. Of the cervical high-grade squamous intraepithelial lesion cases, 100% had high-risk HPVs of which 87 (75%) were found to have HPV 16. The findings demonstrate that a significant number of low-grade vulvar and vaginal lesions contain high-risk HPV types, supporting their designation as low-grade intraepithelial lesions rather than flat condylomas. The low frequency of HPV 16 in VIN 1 compared with VIN 3 suggests they are distinct lesions or that HPV 16 is critical in the progression to VIN 3. Finally, comparison of the distribution of HPV in the vagina and vulva suggests that VaIN is more closely related to cervical intraepithelial neoplasia than to VIN.     

Ki-67, cyclin E, and p16INK4 are complimentary surrogate biomarkers for human papilloma virus-related cervical neoplasia.

Prior studies of Ki-67, cyclin E, and p16 expression have suggested that these biomarkers may be preferentially expressed in cervical neoplasia. This study examined and compared the distribution of staining for these three antigens in 1) normal and reactive epithelial changes, 2) diagnostically challenging cases (atypical metaplasia and atypical atrophy), 3) squamous intraepithelial lesions (SIL), and 4) high-and low-risk human papilloma virus (HPV) type-specific SIL. One hundred four epithelial foci from 99 biopsies were studied, including low-grade squamous intraepithelial lesions (LSIL; 24), high-grade squamous intraepithelial lesions (HSIL; 36), mature or immature (metaplastic) squamous epithelium (29), and atrophic or metaplastic epithelium with atypia (15). Cases were scored positive for Ki-67 expression if expression extended above the basal one third of the epithelium, for cyclin E if moderate to strong staining was present, and for p16 if moderate to strong diffuse or focal staining was present. HPV status was scored by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis of extracted DNA. Immunohistochemical findings were correlated with histologic and viral data. Overall, a histologic diagnosis of SIL correlated strongly with all of the biomarkers used (p <0.001). Positive scores for Ki-67, cyclin E, and p16 were seen in 68.4%, 96.7%, and 100% of LSILs and 94.7%, 91.6%, and 100% of HSILs, respectively. Positive predictive values of these three biomarkers for HPV were 82.4%, 89.5%, and 91.4%, respectively. The positive predictive value for HPV of either cyclin E or p16 was 88.7%. Strong diffuse staining for p16 was significantly associated with high-risk HPV-associated lesions. Normal or reactive epithelial changes scored positive for the three biomarkers in 7.7%, 8.0%, and 12%, respectively. Limitations in specificity included minimal or no suprabasal staining for Ki-67 in immature condylomas and occasional suprabasal staining of reactive epithelial changes (10%), diffuse weak nuclear cyclin E staining in some normal or metaplastic epithelia, and diffuse weak basal p16 staining and occasional stronger focal positivity in normal epithelia. Ki-67, cyclin E, and p16 are complementary surrogate biomarkers for HPV-related preinvasive squamous cervical disease. (Because cyclin E and p16 are most sensitive for LSIL and HSIL [including high-risk HPV], respectively, use of these biomarkers in combination for resolving diagnostic problems, with an appreciation of potential background staining, is recommended.)     

Human Papillomavirus and Overexpression of P16INK4a in Nonmelanoma Skin Cancer

BACKGROUND: P16INK4a overexpression has been identified as a specific biomarker in high-risk human papillomavirus (HPV)-infected cervical (pre)cancer lesions. OBJECTIVE: To evaluate the overexpression of this cyclin-dependent kinase inhibitor in skin tumors depending on HPV infections, we analyzed normal skin, benign skin disease, and skin cancer specimens. METHODS: Biopsies of 23 patients with normal histology (3), psoriasis (2), verrucae vulgaris (2), actinic keratoses (5), squamous cell carcinoma (SCC) in situ (3), Bowen's carcinoma (1), and SCC (7) were analyzed. Specimens of 23 patients were immunostained using the monoclonal antibody E6H4 specific for p16INK4a. HPV status was assessed by a polymerase chain reaction (PCR) system to detect all currently known HPV types. MY (MY09/MY11 and MYN9/MYN10)-, CP (CP65/CP70 and CP66/CP69)-nested PCR, and three single PCR methods CN1, CN3, and CN4 were used in a first step, and HPV typing was performed by restriction fragment length polymorphism analysis. Only beta-globin-positive patients were included in this study. RESULTS: HPV DNA was detected in all actinic keratoses, SCC in situ, Bowen's carcinoma, and SCC, in 50% (one of two) of verrucae vulgaris, in 66% (two of three) of normal skin, and in none of two psoriasis. P16INK4a expression was not detected in normal skin, psoriasis, and verrucae vulgares. Overexpression of p16INK4a was detected in a subset of dysplastic cells (10% to 80%) of all skin (pre)cancer lesions such as actinic keratoses, SCC in situ, Bowen's carcinoma, and SCC infected with HPV independent of sun exposure. CONCLUSION: P16INK4a appears to be overexpressed in a portion of dysplastic cells from actinic keratoses and SCC. Further studies to examine the association of HPV infection and the overexpression of p16INK4a are warranted.     

P16 and human papillomavirus in sinonasal squamous cell carcinoma

Human papillomavirus (HPV) in oropharyngeal squamous cell carcinoma (SCC) is a well‐known cause and prognostic indicator, and the utility of p16 as a surrogate marker for HPV status has been established. P16 and its relationship with HPV have not been defined in sinonasal malignancy nor has a link with outcomes been established. Patients with sinonasal SCC from 2011 to 2017 were identified from our pathology database. P16 immunohistochemistry and HPV RNA in situ hybridization were performed on tissue specimens. Forty‐seven patients were included. Disease‐free survival for p16+ patients was significantly higher than p16? patients (P = .043). Fewer HPV+ patients died (P = .052) or experienced recurrence (P = .0437). Odds ratio between p16 and HPV status was 14.19 (95% CI: 1.72, 442.03). Our findings demonstrate improved survival in both the p16+ and HPV+ groups and a positive association between p16 and HPV. There may be similar potential for modifying classification for HPV+ sinonasal SCC.     

Combined p53 and retinoblastoma protein detection identifies persistent and regressive cervical high-grade squamous intraepithelial lesions

Most cervical high-grade squamous intraepithelial lesions (HSILs) persist, but approximately one third regress (ie, no HSIL in follow-up biopsies). To identify factors related to histologic proven persistence or regression. Twenty-eight small histologic (marker) biopsies with adequate follow-up were analyzed for human papillomavirus (HPV) genotypes and different immunoquantitative proliferation, cell cycle regulation, and differentiation markers. All cases had a biopsy-interval between the marker and first follow-up biopsy of at least 100 days (median, 8.2 months; range, 3.4-22.5 months). Follow-up was classified as regression or persistence. All lesions were high-risk (hr) HPV and p16 positive, 63% for HPV-16 or HPV-16 mixed with other hr genotypes, while 37% had other hrHPV types. The marker biopsies of the persistent HSILs had lower p53 and retinoblastoma protein (pRb) detected in the deep half of the epithelium (P = 0.001 and 0.02, respectively) than nonpersistent HSILs. The degree of positivity of p16, Ki-67, cyclin D1, lesion extent, positivity of the resection margins, and patient age were all unrelated to persistence or regression. Lesions with HPV-16 or mixed-16 genotypes had a significantly lower percentage of pRb (P = 0.02), p53 (P = 0.02), and cyclin D (P = 0.04) positive nuclei in the deep epithelial layers. In agreement with this, type-16 positive HSILs had a lower regression percentage than those with other HPV types, but the difference was not significant. HSILs with combined negativity/low positivity for p53 and pRb protein in small histologic biopsies are highly likely to persist, contrasting those in which one of these cell cycle regulators is strongly positive (p53 > 15%; pRb > 40%).     

Morphologic features of conventional squamous cell carcinoma of the oropharynx: 'keratinizing' and 'nonkeratinizing' histologic types as the basis for a consistent classification system

Morphologic assessment is one of the most basic tools that pathologists use to classify tumors. Human papillomavirus (HPV)-related squamous cell carcinoma of the oropharynx has unique morphologic features that can be readily recognized under the microscope. Yet, these features are not widely recognized or uniformly reported. In our practice, we group oropharyngeal squamous cell carcinomas into 'nonkeratinizing', 'nonkeratinizing with maturation', and 'keratinizing' histologic types. The 'nonkeratinizing' type has a very strong association with HPV, while the 'keratinizing' type has a weaker association with the virus. 'Nonkeratinizing with maturation' is intermediate but much more closely related to the 'nonkeratinizing' type. This classification system parallels that of sinonasal and nasopharyngeal squamous cell carcinomas where nonkeratinizing squamous cell carcinomas are widely recognized histologic variants. This review will discuss this classification system and its utility in routine clinical practice.     

Detection of human papillomavirus in small cell carcinomas of the anus and rectum

Small cell carcinomas represent <1% of colorectal/anal carcinomas and have a poor prognosis. Anorectal squamous cell carcinomas are often associated with high-risk human papillomavirus (HPV) infection, similar to squamous and small cell carcinomas of the uterine cervix. In HPV infection, the oncoprotein E7 inactivates the tumor suppressor Rb, leading to p16 upregulation; however, in small cell carcinomas, the Rb pathway is often blocked by other mechanisms; thus, increased p16 may not indicate HPV infection. P16 immunohistochemistry (IHC) may have a limited role in evaluating small cell carcinomas for HPV infection. Formalin-fixed, paraffin-embedded tissue sections of previously diagnosed small cell carcinomas of the anus (n=5) and rectum (n=11) were subjected to IHC for p16, CDX2, and p63, followed by in situ hybridization for high-risk HPV. All (100%) cases of anal and rectal small cell carcinomas were positive for p16, and 100% of anal and 82% of rectal small cell carcinomas were positive for high-risk HPV. The majority of cases showed low or very low HPV copy numbers. In 6 cases, HPV was detected only by using the HPV-16 genotype-specific assay detecting very low copy numbers (1 to 2 viral copies). The majority of tumors expressed p63, which was more pronounced in the anal tumors. CDX2 expression was observed predominantly in rectal tumors. High-risk HPV can be detected using in situ hybridization in the majority of anorectal small cell carcinomas, which are uniformly p16 positive by IHC. HPV-targeted therapy could result in better control of these aggressive neoplasms.     

Role of human papillomavirus typing in diagnosis and clinical decision making for a giant verrucous genital lesion

A 60-year-old man presented with a 12.0 x 10.0-cm exophytic, verrucous genital plaque. Multiple biopsy specimens were evaluated by standard histologic analysis and polymerase chain reaction assays for human papillomavirus (HPV) deoxyribonucleic acid. All biopsy specimens showed histopathologic changes consistent with giant condyloma of Buschke-Lowenstein (GCBL), were uniformly positive for HPV 6/11, and showed a weaker signal for HPV 16. Published reports suggest that the presence of HPV may be useful in differentiating GCBL from verrucous carcinoma (VC), but absence of "high-risk" HPV types in GCBL cannot exclude focally invasive squamous cell carcinoma. Screening for HPV may be a helpful adjunct in differentiating GCBL from VC, but histopathologic criteria for malignancy should take precedence over HPV typing when determining management.     

Comparing Outcomes for Patients with Human Papillomavirus (HPV) Type 16 versus Other High-Risk HPV Types in Oropharyngeal Squamous Cell Carcinoma

Human papillomavirus (HPV)-associated oropharyngeal squamous cell carcinoma (OPSCC) is related to improved treatment outcomes. What remains unclear is whether all HPV DNA genotypes carry similar prognostic relevance. We aimed to evaluate disease control and survival outcomes by HPV DNA genotype. Patients with primary OPSCC without distant metastases treated with curative intent were retrospectively identified from an IRB-approved institutional database. Patients that underwent HPV DNA polymerase chain reaction (PCR) testing with available genotype were included and dichotomized by the presence of HPV type 16 (HPV-16) or other high-risk HPV genotype (HPV-non16). Overall survival (OS), disease-free survival (DFS), locoregional control (LRC) and distant control (DC) were determined using the Kaplan–Meier method and compared using the log-rank test. In our cohort of 193 patients treated from 2012 to 2018 with HPV DNA PCR, 10% were detected as HPV-non16 high-risk types. Patients with HPV-16 were significantly younger than those with HPV-non16, but no other baseline factors were associated with HPV-non16. With a median follow-up of 42.9 months, there were no significant differences in outcomes between the HPV-16 and HPV-non16 groups for 3-year OS (87.7% v. 73.6%), DFS (82.9% v. 68.7%), LRC (92.8% v. 88.5%) or DC (91% v. 89.2%). There is no statistically significant difference in outcomes between OPSCC with HPV-16 and HPV-non16 high-risk genotypes in our cohort, though trends of overall worse survival and disease-free survival in HPV-non 16 OPSCC were seen. Further studies with larger cohorts of patients with HPV-non 16-associated OPSCC are required to make definitive conclusions regarding the prognostic and clinical significance of HPV type.     

Morphologic Features of Conventional Squamous Cell Carcinoma of the Oropharynx: ‘Keratinizing’ and ‘Nonkeratinizing’ Histologic Types as the Basis for a Consistent Classification System

Morphologic assessment is one of the most basic tools that pathologists use to classify tumors. Human papillomavirus (HPV)-related squamous cell carcinoma of the oropharynx has unique morphologic features that can be readily recognized under the microscope. Yet, these features are not widely recognized or uniformly reported. In our practice, we group oropharyngeal squamous cell carcinomas into ‘nonkeratinizing’, ‘nonkeratinizing with maturation’, and ‘keratinizing’ histologic types. The ‘nonkeratinizing’ type has a very strong association with HPV, while the ‘keratinizing’ type has a weaker association with the virus. ‘Nonkeratinizing with maturation’ is intermediate but much more closely related to the ‘nonkeratinizing’ type. This classification system parallels that of sinonasal and nasopharyngeal squamous cell carcinomas where nonkeratinizing squamous cell carcinomas are widely recognized histologic variants. This review will discuss this classification system and its utility in routine clinical practice.