Laryngeal papillomatosis: molecular, histopathological, and clinical evaluation

Approach to small biopsies in the larynx

Small biopsies in the larynx can make a definitive diagnosis challenging due to the sampling or tangential sectioning. The differential diagnosis can be divided into mucosal lesions (squamous papillomas, intraepithelial dysplasia, and invasive squamous cell carcinoma) or submucosal lesions (vocal cord polyps/nodules, amyloidosis, granular cell tumor, rhabdomyoma, neuroendocrine neoplasms, salivary gland tumors, and cartilaginous tumors). Diagnostic criteria (both morphologic and immunohistochemical) are reviewed to arrive at a diagnosis even on small biopsy.

Risk factors associated with severe recurrent respiratory papillomatosis

Background

Objectives

Methods

Results

Conclusion

HPV RNA in-situ hybridization as a diagnostic aid in papillary laryngeal lesions

OBJECTIVES

In the larynx, differentiating squamous papillomas from de-novo papillary squamous dysplasias or squamous cell carcinomas (SCC) has significant consequences for management. Overlapping clinical presentations and cytologic changes across the spectrum of papillary lesions presents diagnostic challenges for otolaryngologists and pathologists. In this study, we evaluate whether ribonucleic acid (RNA) in-situ hybridization (ISH) for low-risk and high-risk human papillomavirus (HPV) can help distinguish these lesions.

METHODS

We constructed tissue microarrays from 97 papillary laryngeal lesions, including 61 squamous papillomas, two papillomas with dysplasia, two SCCs-ex papilloma, 14 papillary squamous dysplasias, and 18 papillary SCCs identified at the Johns Hopkins Hospital between 2000 and 2017. We performed RNA ISH using probes for low-risk and high-risk HPV types.

RESULTS

Low-risk HPV RNA was identified in 55 benign papillomas (90%), two papillomas with dysplasia (100%), and two SCCs-ex papilloma (100%) but was absent in de-novo papillary dysplasias and SCCs (0%). High-risk HPV RNA ISH was positive only in four papillary SCC (22%). Overall, low-risk HPV RNA ISH was 90% sensitive and 89% specific for benign papillomas with a positive predictive value of 93% and negative predictive value of 84%. In contrast, high-risk HPV was 20% sensitive for SCC.

CONCLUSION

Low-risk HPV RNA ISH is a useful diagnostic adjunct for distinguishing laryngeal squamous papillomas from papillary squamous dysplasia and SCC. However, it is not entirely specific for benign processes as it is also retained in papillomas with dysplasia and SCCs-ex papilloma. Because high-risk HPV is rare in papillary laryngeal lesions, high-risk HPV RNA ISH has limited utility.

LEVEL OF EVIDENCE

Level 4 Laryngoscope, 130:955-960, 2020.

Age of onset of recurrent respiratory papillomatosis: a distribution analysis

OBJECTIVE

Distribution of age of onset of recurrent respiratory papillomatosis (RRP) is generally described to be bimodal, with peaks at approximately 5 years and 30 years. This assumption has never been scientifically confirmed, and authors tend to refer to an article that does not describe distribution. Knowledge of the distribution of age of onset is important for virological and epidemiological comprehension. The objective of this study was to determine the distribution of age of onset of RRP in a large international sample.

DESIGN

Cross-sectional distribution analysis.

PARTICIPANTS

Laryngologists from 12 European hospitals provided information on date of birth and date of onset of all their RRP patients treated between 1998 and 2012. Centers that exclusively treated either patients with juvenile onset RRP or patients with adult onset RRP, or were less accessible for one of these groups, were excluded to prevent skewness.

MAIN OUTCOME MEASURES

A mixture model was implemented to describe distribution of age of onset. The best fitting model was selected using the Bayesian information criterion.

RESULTS

Six hundred and thirty-nine patients were included in the analysis. Age of onset was described by a three component mixture distribution with lognormally distributed components. Recurrent respiratory papillomatosis starts at three median ages 7, 35 and 64 years.

CONCLUSIONS

Distribution of age of onset of RRP shows three peaks. In addition to the already adopted idea of age peaks at paediatric and adult age, there is an additional peak around the age of 64.

HPV associated with recurrent respiratory papillomatosis

Papillomaviruses are members of the Papillomaviridae family. Over 150 HPV types have been identified. Recurrent respiratory papillomatosis (RRP) is a chronic condition caused by HPV characterized by recurrent papillomas of the respiratory tract, mainly the larynx. During the early stages, the condition presents with hoarseness, while more advanced disease presents with stridor and respiratory distress. There is no specific cure and treatment consists of repeated surgical procedures to remove the papillomas. Most patients eventually go into remission, but some suffer for many years with this condition, which may be fatal. HPV-6 and HPV-11 are the HPV types most commonly associated with RRP. Although most studies have found RRP due to HPV-11 to be more aggressive than disease due to HPV-6, the variability in disease aggressiveness is probably multifactorial. Information regarding the current epidemiology, molecular diversity and host immune responses is important for strategizing ways to reduce disease. Data on HPV genotypes associated with RRP would provide valuable information for vaccination programs to reduce the incidence of these genotypes in mothers and, in the long term, reduce the incidence of RRP in children. This review focuses on HPV-6 and HPV-11 as the HPV types that cause RRP, and discusses the viral genome and replication, clinical presentation of RRP, current techniques of diagnosis and genotyping, and the molecular diversity of HPV-6 and HPV-11.

Detection and typing of low-risk human papillomavirus genotypes HPV 6, HPV 11, HPV 42, HPV 43 and HPV 44 by polymerase chain reaction and restriction fragment length polymorphism

A novel PCR-restriction fragment length polymorphism assay (PCR-RFLP) was developed for sensitive detection and reliable differentiation of five low-risk human papillomavirus (lr-HPV) genotypes: HPV 6, HPV 11, HPV 42, HPV 43 and HPV 44, as well as differentiation of prototypic and non-prototypic HPV 6 genomic variants. The assay is based on the amplification of a 320-bp fragment of the HPV E1 gene and subsequent analysis of PCR-products with BsaJI and HinFI. Testing on plasmid standards showed that PCR-RFLP enabled simple and reliable identification and differentiation of five targeted lr-HPV genotypes and could detect reproducibly down to 10 copies of viral genome equivalents per PCR. The PCR-RFLP showed almost complete agreement with previously obtained genotyping results on 42 HPV-DNA negative samples and 223 HPV-DNA positive samples (45 HPV 6, 34 HPV 11, 35 HPV 42, 10 HPV 43, 24 HPV 44 positive samples and 75 samples containing 28 non-targeted HPV genotypes). The novel assay is simple and robust, does not require any sophisticated equipment and can be of great value for epidemiological studies, particularly in settings in which financial resources are limited.

HPV types causing juvenile recurrent laryngeal papillomatosis in South Africa

OBJECTIVES

To identify human papillomavirus (HPV) types associated with juvenile onset recurrent laryngeal papillomatosis (RLP) in southern Africa, to determine if there is a correlation between HPV type and disease aggressiveness and to determine the diagnostic and prognostic value of rapid molecular techniques for detection and typing of HPV using laryngeal biopsies.

METHODS

Laryngeal biopsies from patients undergoing surgery for RLP were screened for HPV using conventional and real-time PCR techniques. Amplicons were sequenced to determine the HPV type involved. Clinical features were correlated with HPV type.

RESULTS

HPV was identified in papillomata from 18 out of 19 patients. Only HPV-6 and HPV-11 were identified, with no co-infections. There was 100% concordance between conventional and real-time PCR techniques. Patients with HPV-11 disease required more procedures and tended to have higher Derkay scores than those with HPV-6 disease. The HPV types identified in our patients were genetically similar to HPV types from geographically distinct regions.

CONCLUSIONS

RLP in our patient population appears to be exclusively due to HPV-6 or HPV-11. HPV-11 disease appears to be more aggressive than HPV-6 disease. Identification of the HPV types provides motivation for inclusion of vaccines against these types in vaccination programs to protect women against infection and subsequently reduce the incidence of RLP.

Human papillomavirus genotype specificity of hybrid capture 2 low-risk probe cocktail

A genotyping study of 285 Hybrid Capture 2 low-risk probe cocktail-positive specimens showed cross-reactivity with several untargeted human papillomavirus genotypes. Cross-reactivity was often clinically beneficial due to the detection of untargeted low-risk genotypes. A total of 8.4% of positive results, usually weak, were due to cross-reactivity with high-risk genotypes. Establishment of a gray zone is recommended.

Detection and differentiation of human papillomavirus genotypes HPV-6 and HPV-11 by FRET-based real-time PCR

A real-time PCR (RT-PCR) assay was developed based on fluorescence resonance energy transfer (FRET) hybridization probe technology, allowing very sensitive and specific detection of HPV-6 and HPV-11, reliable differentiation of HPV-6 and HPV-11, as well as prototypic and non-prototypic HPV-6 genomic variants, in a single PCR reaction. The primers and probe were designed on the basis of multiple alignments of 74 HPV-6 E2 gene sequences and 20 HPV-11 E2 gene sequences. Testing on defined plasmid standards showed that the RT-PCR allowed simple and reliable identification of HPV-6 and HPV-11 using type specific amplification followed by probe-specific post-amplification dissociation analysis. Sensitivity, assessed by probit analysis at a 95% detection level, was 42.9, 43.4, and 25.3 DNA copies per assay for prototypic and non-prototypic HPV-6 variants and HPV-11, respectively. The results obtained by the developed assay on 51 HPV DNA-negative samples and 149 HPV DNA-positive samples, including 81 HPV-6 positive samples (19 prototypic and 62 non-prototypic HPV-6 variants), 28 HPV-11 positive samples, 10 samples of HPV-44 and HPV-74 (the closest relatives of HPV-6 and HPV-11) and 30 samples of 15 other important alpha HPV, showed complete agreement with those obtained with the INNO-LiPA human papillomavirus (HPV) Genotyping Assay and HPV-6 E2 and E6 gene sequencing.

Molecular Events in the Progression of Recurrent Respiratory Papillomatosis to Carcinoma

Context.—Identification of the type of human papillomavirus (HPV) by polymerase chain reaction and sequencing to determine coinfection or superinfection (by more than 1 HPV type) and other molecular events have not been reported in a series of patients exhibiting the morphologic spectrum of recurrent respiratory papillomatosis progressing to carcinoma.

Design.—Four cases of juvenile-onset recurrent respiratory papillomatosis progressing to carcinoma (no history of smoking or irradiation in 2 cases) were studied. Morphologically distinct foci (squamous papilloma, pulmonary papillomatosis, squamous dysplasia subjacent to carcinoma, and squamous carcinoma) were subjected to laser capture microdissection and polymerase chain reaction amplification using general primers in addition to type-specific primers for HPV types 16 and 18. Direct sequencing of polymerase chain reaction products identified the type of HPV. The tissue sections were immunostained using antibodies to p53, pRb, p21WAF1, and p16 proteins with a semiquantitative assessment.

Results.—Human papillomavirus 11 was the only type of HPV identified in all lesions of all cases associated with recurrent respiratory papillomatosis. There was a marked increase in p53 protein expression in foci of dysplasia and carcinoma as compared to squamous papilloma and pulmonary papillomatosis. An inverse correlation between p53 and p21WAF1 protein expression was noted in all lesions. pRb protein expression increased from the benign to the malignant end of the spectrum. p16 protein was expressed in all lesions.

Conclusions.—Infection by HPV-11 may be an early event associated with progression of recurrent respiratory papillomatosis to carcinoma. Increased expression of p53 and pRb proteins and a reduced expression of p21WAF1 protein appear to be significant subsequent events.

Human papillomavirus in larynx

OBJECTIVES

The core of the present clinical and basic research knowledge of laryngeal human papillomavirus (HPV) infection is described.

STUDY DESIGN

Review.

METHODS

A computer-aided search of MEDLINE database supplemented by hand searches of key journals was conducted.

RESULTS

One of the tumor-promoting factors in the larynx is the HPV found both in normal laryngeal epithelium and in laryngeal tumors. The most important manifestation of laryngeal HPV infection is laryngeal papillomatosis, a rare disease caused by HPV types 6 and 11. In laryngeal carcinogenesis, the role of HPV remains uncertain. The means of transmission of HPV are partly unknown, and the course of laryngeal HPV infection is unpredictable and variable. Treatment of laryngeal papillomatosis is based on surgery, especially on CO2 laser and shaver. Alpha-interferon is the drug of choice in patients whose response to surgery is poor. However, neither interferon nor other antiviral drugs are able to eradicate the virus from laryngeal mucosa. Little is known about immunological mechanisms involved in laryngeal HPV infection, but in defense against HPV cellular immunity is considered a more important mechanism than humoral immunity. A good experimental model of HPV infection is lacking in which the entire viral life cycle can take place. Organotypic cell cultures (collagen rafts) are useful, but the rate-limiting step in this method is the difficulties in culturing HPV-positive epithelial cells.

CONCLUSIONS

Although laryngeal papillomatosis is clinically well defined, the mechanisms and treatment modalities of laryngeal HPV infection need further investigations.

Human papillomavirus infection in esophageal carcinomas: a study of 121 lesions using multiple broad-spectrum polymerase chain reactions and literature review

To elucidate the putative role of human papillomavirus (HPV) infection in the etiology of esophageal cancer, 121 formalin-fixed, paraffin-embedded specimens originating from a non-high-incidence area for this carcinoma, from Slovenia, were screened for HPV infection using eight different polymerase chain reactions (PCR). Three different HPV consensus primer sets and four primer sets specific for HPV types 6, 16, and 18 failed to detect HPV DNA sequences in any of the tumor samples. Fragments of human beta-globin gene that served as internal controls were successfully amplified from 120 of 121 specimens. Our study confirms the opinion that most esophageal cancers originating from non-high-incidence geographic areas of this cancer are not associated with HPV infection. According to the studies reviewed, it is likely that HPV infection plays a much more significant role in esophageal carcinogenesis in those areas of the world with a high incidence of ESCC.

Langerhans cells in human papillomaviruses types 6/11 associated laryngeal papillomas

Some studies have shown a reduced density of Langerhans cells (LCs) within epithelium infected by human papillomaviruses (HPV) types 16/18. However, data on a correlation between HPV types 6/11 infection and LCs have been missing. To solve this problem, we analysed 24 biopsy specimens of laryngeal papillomas, selected randomly, 20 multiple and 4 solitary. The presence of HPV 6 and 11 was proven by polymerase chain reaction (PCR) using 2 different sets of primers in 23 biopsy specimens. Abnormalities of the covering stratified squamous epithelium were graded according to the Kambic-Gale classification. LCs were immunohistochemically labelled with 2 different antibodies, CD1a and S100. Quantitative analysis was performed to determine the density of LC per mm2 in different grades of epithelial abnormalities covering laryngeal papillomas. Although no statistically significant differences in the mean number of LCs per mm2 of the cross-sectioned epithelium covering laryngeal papillomas were observed comparing simple, abnormal and atypical hyperplasia groups, the mean number of LCs per mm2 in laryngeal papillomas associated with HPV types 6/11 infection substantially exceeded that of the vocal cord surface epithelium in patients with chronic laryngitis.

Prognostic value of clinical findings in histologically verified adult-onset laryngeal papillomas

A retrospective study of adult-onset laryngeal papilloma was performed to clarify whether any clinical features at the time of diagnosis could predict its course. All patients had a histologically confirmed diagnosis of laryngeal papillomas and were treated at Helsinki University Hospital between 1975 and 1994. Those with adult-onset disease and follow-up exceeding 1 year (n = 74) entered the study. Based on the case records surveyed, results suggested two risk factors for frequent laryngeal procedures: young age at onset of papilloma and a lesion extending to the anterior third to the vocal folds. It was not possible to predict the course of the disease by such clinical findings as symptoms or size or number of primary papilloma lesions. As regards the recurrence of disease, the classic division of adult-onset laryngeal papilloma into solitary and multiple type was not found to be clinically relevant.

Sudden death caused by laryngeal papillomatosis

Laryngeal papillomatosis (LP) is the most frequent benign neoplasm of the larynx. Clinically it causes hoarseness and upper airway obstruction. Though the LP has the potential to endanger life by asphyxiation, this unfortunate outcome is extremely rare. We report the case of a 19-year-old female who suddenly died of asphyxiation caused by massive LP.

Human papillomaviruses: a study of their prevalence in the epithelial hyperplastic lesions of the larynx

This study investigated the prevalence of human papillomavirus (HPV) infection in various laryngeal epithelial hyperplastic lesions using the Kambic classification from simple hyperplasia to invasive squamous cell carcinoma. For detection of HPV infection polymerase chain reaction (PCR) with 3 different HPV consensus primer sets and in situ hybridization were used. The presence of the HPV DNA was detected in only 2 of the 88 specimens tested: HPV type 6 was detected in 1 case of simple hyperplasia and HPV type 16 in 1 case of invasive squamous cell carcinoma. In conclusion, our study suggests that most laryngeal epithelial hyperplastic lesions are not associated with HPV infection and that other pathogenic mechanisms are more important in the etiology of these lesions.

Rapid detection and typing of human papillomaviruses by consensus polymerase chain reaction and enzyme-linked immunosorbent assay

A novel method for the detection and typing of human papillomaviruses (HPV) based on consensus polymerase chain reaction (PCR) using MY09/MY11 primers followed by detection of PCR products in a standard microtiter plate format using a recently developed commercially available standardised PCR ELISA kit (Boehringer Mannheim, Germany) was developed. The reliability and feasibility of the method were evaluated on 140 HPV-positive and 85 HPV-negative DNA samples extracted from different archival clinical specimens. Virtually complete agreement between the results of this novel method and the results of previous in-house PCRs and typing method was obtained. The sensitivity level of the novel method, determined by serial log-dilutions of SiHa cells, is about 50 copies of HPV 16. The PCR-ELISA provides the potential for an automated, simple, rapid and accurate test for detection and typing of HPV in diagnostic virological laboratories.