Prevalence of high-risk human papillomavirus DNA in nonkeratinizing (cylindrical cell) carcinoma of the sinonasal tract: a distinct clinicopathologic and molecular disease entity

Carcinomas of the nose and paranasal sinuses are a heterogeneous group of neoplasms that differ histologically, biologically, and clinically. Some of these tumors are known to harbor high-risk human papillomavirus (HPV) DNA. In an attempt to identify specific phenotypes associated with HPV infection, 39 cases of sinonasal carcinomas were evaluated by PCR for the presence of HPV DNA. The tumors were also studied with a panel of immunohistochemical stains, including p16, p53, and Ki-67 antibodies. Twenty-one cases were identified as keratinizing squamous cell carcinoma (KSCC) with a male-to-female ratio of 3:1. Eight cases were nonkeratinizing (cylindrical cell) carcinoma (NKCa) with a male-to-female ratio of 1:1. Ten cases were sinonasal undifferentiated carcinoma (SNUC), and 9 of these patients were men. HPV DNA, particularly type 16, was detected in 9 cases: 4 of 21 (19%) of KSCC, 4 of 8 (50%) of NKCa, and 1 of 10 (10%) of SNUC. In addition to a higher prevalence of HPV DNA in NKCa, the tumors also showed a distinct immunophenotype characterized by strong and diffuse staining for p16, high labeling scores for Ki-67, and negative or low reactivity to p53. On the other hand, KSCC and SNUC were either negative or weakly reactive to p16 antibodies. KSCC cases were more likely to be positive and more strongly reactive to p53 stain. Unlike KSCC, SNUC had high Ki-67 labeling scores. These observations suggest that NKCa of the sinonasal tract is a distinct histopathologic and molecular disease entity, which should be added to the list of upper aerodigestive tract tumors with strong etiologic relationship to high risk HPV.     

Histologic Identification of Human Papillomavirus (HPV)-Related Squamous Cell Carcinoma in Cervical Lymph Nodes: A Reliable Predictor of the Site of an Occult Head and Neck Primary Carcinoma

Objective Patients with head and neck squamous cell carcinoma (SCC) often present with cervical lymph node metastasis. Occasionally the primary tumor site remains unknown even after thorough investigation. Management of such cases is problematic and may result in over-treatment and consequent increased morbidity. High risk HPV has been advocated recently as an important etiologic factor for a subset of head and neck SCC. These are believed to have a special predilection for the oropharyngeal tonsils and are characterized by nonkeratinizing basaloid morphology, and a strong reactivity to p16 immunostain. Identifying HPV-related SCC in the lymph nodes may thus provide a means for localizing the primary tumor site. Design Ninety-three cases of SCC metastatic to the neck from known primary tumors were classified morphologically into conventional keratinizing SCC (KSCC) and non-keratinizing SCC (NKCa). In situ hybridization (ISH) for high risk HPV as well as immunostaining for p16 were performed on all metastsatic and primary tumors. Results Of the 93 cases of metastatic carcinomas 32 were oropharyngeal, 35 oral, and 26 arose in the laryx/hypopharynx. Twenty-three cases were found to be HPV+ by ISH, of which 22/23 had oropharyngeal origin (P < 0.0001), with 95.7% sensitivity and 85.7% specificity. Twenty-one of these HPV+ oropharyngeal tumors were NKCa (P < 0.0001). The remaining case showed overlapping NKCa/KSCC hybrid morphology. All NKCa were HPV+ and stained diffusely and strongly with p16 antibodies. Conclusion We have demonstrated that HPV status of the lymph node metastasis can be assessed not only by ISH and p16 immunoreactivity but also histomorphologically. In addition, a positive microscopic identification of HPV-related carcinoma is a reliable predictor of oropharyngeal origin.     

Prevalence of human papillomavirus type 16 DNA in squamous cell carcinoma of the palatine tonsil, and not the oral cavity, in young patients: a distinct clinicopathologic and molecular disease entity

Squamous cell carcinoma of the head and neck commonly affects patients in their sixth decade and older, particularly those with a prolonged history of alcohol and tobacco abuse. Less frequently, carcinomas occur in young individuals even in the absence of known risk factors. The purpose of this study is to investigate a possible relationship between these tumors and human papilloma virus (HPV). Thirty-three cases of squamous cell carcinoma of the head and neck in young patients under the age of 40 years were studied: 15 oral, 11 tonsillar, and 7 laryngeal. HPV DNA was detected by polymerase chain reaction in 10 tonsillar and 2 laryngeal carcinomas and in none of the oral tumors. Of the 12 HPV-positive tumors, 11 were HPV16 and 1 was HPV31. HPV-positive tumors had a distinct nonkeratinizing basal cell morphology, they stained diffusely and strongly with p16 antibodies, had higher Ki-67 and lower p53 staining scores as compared with the conventional keratinizing HPV negative carcinomas. It is concluded that in young patients high-risk HPV, particularly HPV16, is strongly associated with tonsillar squamous cell carcinoma and some cases of laryngeal, but not oral, tumors. The HPV-positive carcinomas have a distinct histopathologic and immunophenotypic features.     

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.     

Expression of calretinin,thrombomodulin, keratin 5, and mesothelin in lung carcinomas of different types: an immunohistochemical analysis of 596 tumors in comparison with epithelioid mesotheliomas of the pleura

Several immunohistochemical markers, among them calretinin, thrombomodulin (CD141), keratin 5, and mesothelin, have been documented or suggested as useful markers for positive identification of mesothelioma and to differentiate it from pulmonary adenocarcinoma; numerous studies have documented their variable specificity. However, expression of these markers in other types of lung carcinomas has not been systematically explored, although these tumors can enter in the differential diagnosis of mesothelioma. In this study we immunohistochemically evaluated 596 lung carcinomas of different types for the four above-mentioned mesothelioma markers, all of which reacted with a great majority of epithelioid mesotheliomas studied for comparison. Calretinin expression was common in giant cell carcinomas (67%), small cell carcinomas (49%), and large cell carcinomas (38%), whereas it was rare in usual adenocarcinomas but slightly more common in those with neuroendocrine differentiation (11% and 17%, respectively). Thrombomodulin was present in all keratinizing squamous carcinomas and the great majority (87%) of nonkeratinizing tumors in a membrane-staining pattern. It was moderately common in small cell (27%) and large cell carcinomas (25%) but relatively rare in adenocarcinomas (13%). Keratin 5 was expressed in all keratinizing and the great majority (87%) of nonkeratinizing squamous carcinomas, and a majority of large cell carcinomas (56%) and some small cell carcinomas (27%). It was rare in acinar adenocarcinomas (12%) and absent in those with neuroendocrine differentiation. Mesothelin was present in more than half (53%) of adenocarcinomas and a minority (13%) of large cell carcinomas but was absent in small cell carcinomas. In squamous carcinomas it was more often seen in nonkeratinizing versus keratinizing tumors (31% vs 16%). These results show that each of these "mesothelioma" markers reacts with different subsets of pulmonary carcinomas with a variable frequency; this should be considered when using these markers in the differential diagnosis of thoracic tumors.     

Lymphoepithelioma of the oropharynx

Lymphoepithelioma is common in the nasopharynx, but its presence elsewhere in Waldeyer's ring is rare. Thirteen patients with lymphoepithelioma in the tonsil and base of the tongue have been treated at our institution. At initial examination, all 13 patients had advanced clinical disease. Five years after their initial treatment, seven patients were alive and free of disease. Radiation therapy controlled local and regional disease in 10 (77%) patients, yet three of these died of distant metastasis. Patients with lymphoepithelioma have a significantly better prognosis (p less than 0.05) than do patients with either nonkeratinizing or keratinizing high-grade oropharyngeal carcinoma. Early recognition and combined therapy may further improve the prognosis. Differentiation of lymphoepithelioma from other high-grade squamous cell carcinomas of the oropharynx is important to guide treatment and to provide prognostic information.     

Human papillomavirus and gene mutations in head and neck squamous carcinomas

Background: Human papillomavirus (HPV) infection is implicated as an aetiological factor in head and neck squamous carcinomas (HNSCC), especially in the tonsils of the oropharyngeal region. This study investigates the frequency of HPV infection, p16 and p53 tumour profile and mutations in epidermal growth factor receptor (EGFR), Kirsten RNA Associated Rat Sarcoma 2 Virus (KRAS) and B‐Raf proto‐oncogene serine/threonine protein kinase (BRAF) genes in tonsillar and non‐tonsillar HNSCCs and correlates with clinical outcome and histopathological parameters in previously unstudied cohort of patients. Methods: A retrospective clinical study was performed utilising the demographic data and pathological specimens from 60 out of 726 head and neck cancer patients. Smoking and alcohol history, tumour staging, treatment and outcomes were recorded. Histopathology and immunochemistry for p16 and p53 was performed and HPV DNA was detected with polymerase chain reaction. Genomic DNA from all cancers were analysed for somatic mutations of EGFR, BRAF and KRAS genes. Results: 20 (33%) of 60 cases were tonsillar squamous carcinomas and 38 (66%) were non‐tonsillar. 19 (95%) of the 20 tonsillar cancers and three (8%) of 38 non‐tonsillar patients were patients who were HPV 16‐positive. Nine (47%) of the 19 HPV 16‐positive tonsillar cases were p16 positive. Gene mutations were rare. There was a statistically significant (P < 0.05) improved survival of patients with HPV positive tonsillar tumours, younger age and non‐smokers. Conclusion: Although limited in numbers, this study reinforces the role of HPV infection in HNSCC and its association with a more favourable clinical course in younger non‐smokers worldwide. Gene mutation frequencies were low in all cancers tested and routine testing not recommended.     

Ciliated Adenosquamous Carcinoma: Expanding the Phenotypic Diversity of Human Papillomavirus-Associated Tumors

This study describes a unique subset of ciliated, human papillomavirus (HPV) related, adenosquamous carcinomas (AsqCA) of the head and neck that in contrast to most AsqCA, often show areas with lower grade cytonuclear features. They are comprised of largely non-keratinizing squamous cell carcinoma components with cystic change, gland formation, mucin production, and cilia in tumor cells. Seven cases of ciliated AsqCA were retrieved. Site distribution was as follows: palatine tonsil—3/7, base of tongue—1/7, and neck (unknown primary site)—3/7. Despite the occasional resemblance to mucoepidermoid carcinoma (MEC), the tumors showed focal keratinizing morphology and atypia, and all tumors were negative for MAML2 rearrangements. Oropharyngeal and neck tumors were uniformly p16 positive and showed punctate staining by in situ hybridization for high risk HPV DNA. There were two distant metastases (lung), and one tumor related death. Thus, ciliated AsqCA are HPV-associated lesions that pose unique pitfalls, closely mimicking MEC and other salivary gland tumors. These tumors add to the list of those which defy the dogma that ciliated epithelium always equates to a benign process.     

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.     

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.     

HPV Positive Squamous Cell Carcinoma of the Oropharynx. Are we Observing an Unusual Pattern of Metastases?

To describe the clinical, histopathologic, immunohistochemical and molecular features of human papilloma virus (HPV)+ squamous cell carcinomas of the oropharynx that had an atypical clinical course. Methods and Results: Four patients with HPV+ oropharyngeal squamous cell carcinoma (OPSCC) were identified retrospectively based on unanticipated clinical behavior. The histopathology, immunohistochemistry and molecular studies of both the primary tumor and the metastases were analyzed to look for any predictors to explain the clinical course. The four patients were all male (average age 55) who presented initially with a neck mass and had stage IVA disease. Three of the primary tumors were nonkeratinizing squamous cell carcinoma and one case was a hybrid tumor of both high-grade squamous cell carcinoma and nonkeratinizing type, and all were p16 and HPV 16/18 positive. All patients received concurrent chemoradiation as primary therapy and had a complete response. Disease-free survival ranged from 7 to 15 months and metastases in 3 patients occurred only in bone, including the sternum, humerus, clavicle, and vertebrae. In one patient, distant metastases were identified in the pancreas, liver, lung and skull base. All metastatic lesions were nonkeratinizing morphology and were p16 and/or HPV positive. Two patients died of their disease, one patient is alive with disease and one patient is disease-free. Although infrequent, unanticipated clinical outcomes can occur in HPV-related OPSCC including distant metastases and bone-only metastases. The tumor morphology of the metastases was comparable to the primary and retained p16 and HPV expression.     

Detection of human papillomavirus in formalin-fixed, invasive squamous carcinomas using the polymerase chain reaction

We analyzed 88 formalin-fixed, paraffin-embedded invasive squamous carcinomas for human papillomavirus-related DNA sequences (HPV types 16 and 18) following in vitro gene amplification using the polymerase chain reaction. HPV DNA sequences were found in 35 of 50 (70%) carcinomas of the anogenital region, including four of four (100%) anal, six of eight (75%) vulvar, nine of 14 (64%) vaginal, two of five (40%) penile, and 14 of 19 (74%) cervical tumors. Nine of 25 (36%) oropharyngeal squamous carcinomas contained HPV DNA sequences, including four of 10 (40%) laryngeal, three of eight (38%) buccal, and two of seven (29%) glossal tumors. HPV DNA sequences were not found in 13 esophageal carcinomas. Of the 44 cases that contained viral DNA, HPV-16 was detected in 41 cases (93%) and HPV-18 in five cases (11%), while both types were found in two cases (one anal and one vulvar). HPV DNA sequences were found in 43 of 83 (52%) nonverrucous and in one of five (20%) verrucous carcinomas, but this difference was not significant. These findings demonstrate that HPV DNA sequences are more frequently associated with anogenital than oropharyngeal squamous carcinomas and can be readily detected in routinely processed tissues using the polymerase chain reaction.     

Human Papillomavirus (HPV) Related Carcinomas of the Upper Aerodigestive Tract

Epidemiologic, clinical, morphologic and molecular evidence show that high risk HPV, particularly type 16, is a prerequisite for some carcinomas of the upper aerodigestive tract (UADT), particularly tonsil and base of tongue. Sexual transmission is an important mode of infection while tobacco use and excessive drinking are not considered risk factors. HPV + tumors are distinct clinically and pathologically. They are more common in young patients (<40 years) with a male to female ratio of 4:1. They usually present as a small or occult primary tumor with advanced neck disease. Microscopically they are non-keratinizing squamous cell carcinomas with basaloid features, excessive mitosis and comedo type necrosis. The tumors have a distinct immunohistochemical profile characterized by strong and diffuse p16 reactivity, low or negative p53 staining and high Ki67 labeling scores. HPV + carcinomas are more radio-sensitive and have a better prognosis than the classical keratinizing SCC of the UADT. An anti-HPV vaccine has recently been made available for prevention of cervical cancer. The impact of the vaccine on the prevalence of HPV related carcinomas of the UADT is currently not known but likely beneficial.     

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.     

Approach to Metastatic Carcinoma of Unknown Primary in the Head and Neck: Squamous Cell Carcinoma and Beyond

Metastatic carcinoma to cervical lymph nodes presenting as an unknown primary is quite common. In most cases, the primary site is ultimately identified. Carcinomas that remain of unknown primary after a thorough search are uncommon. This review will focus on those cases that initially present as unknown primaries, since this is the setting in which pathologists first encounter these cases and in which they play an important role in guiding patient management. Most are squamous cell carcinomas, the majority of which are human papillomavirus (HPV)-related and originate in the palatine tonsils and base of tongue. HPV-related oropharyngeal squamous cell carcinomas are increasing in incidence and have unique clinical and pathologic features that make them particularly likely to present as an unknown primary. Understanding these features has led to improved detection of the primary tumors. Further, even when the primary tumor is not found, prognosis is very dependent on characterization of the tumor HPV status. Papillary thyroid carcinomas may also initially present without a known or clinically detectable primary, either as a neck mass or incidentally in a neck dissection performed for another indication. The latter is a very indolent disease. Finally, primary salivary gland carcinomas may mimic an unknown primary and need to be distinguished from cutaneous metastases to the parotid gland, which may present without a recognized skin tumor. Here, we review the clinical and pathologic features of these entities and provide a systematic approach to their diagnosis.     

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.