MA Birchall

It has been suggested that the link between human papillomavirus (HPV) and head and neck squamous cell carcinoma (HNSCC) is specific to carcinoma of the tonsil. We systematically reviewed studies that tested for HPV16 exposure in anatomically defined sites in the head and neck and a control group. The association between HPV16 and cancer was strongest for tonsil (OR: 15.1, 95% CI: 6.8-33.7), intermediate for oropharynx (OR: 4.3, 95% CI: 2.1-8.9) and weakest for oral (OR: 2.0, 95% CI: 1.2-3.4) and larynx (OR: 2.0, 95% CI: 1.0-4.2). To investigate heterogeneity, further stratification by method of HPV16 detection, suggested that variation in the magnitude of the HPV-cancer association with cancer site was restricted to studies using ELISA: among studies using PCR, the magnitude of the summary odds ratios was similar across the four sites. The association between HPV16 infection and HNSCC in specific sites suggests the strongest and most consistent association is with tonsil cancer, and the magnitude of this association is consistent with an infectious aetiology. However, the method of viral detection may be an important source of heterogeneity. Resolution of this issue will require further studies using both methods, examining associations separately in different sites.

We prospectively studied the latest 60 patients who presented to the ENT Departments of St Mary's and St George's Hospitals with ingested foreign bodies. Localization of the foreign body by the patient was compared to the actual site of the foreign body at removal and graded accordingly. Localization was better the higher the object. When compared with objects above the cricopharyngeus muscle items impacted below this level were poorly localized (P < 0.0001) and lateralized (P < 0.0001). This suggests that for a patient who is able to lateralize a presumptive foreign body within the cervical region, then that object is likely to be above cricopharyngeus and on the side indicated. Further, it is likely to be visible on indirect laryngoscopy and amenable to removal in the casualty department. We hypothesize that the pharyngeal innervation by the vagus and glossopharyngeal nerves provides better sensation than in the oesophagus which is innervated less densely by the vagus and cervical sympathetic nerves.

The larynx is a mucosal organ positioned at the divergence of the respiratory and digestive tracts. It is exposed to a wide variety of environmental components, including foreign antigens, tobacco smoke, laryngopharyngeal reflux and pollutants. The mucosal immune system generates either active immune responses or tolerance, depending on the nature of the antigen and we hypothesize that the larynx is important organ for immunological decision-making in the airway. Because the pig is an ideal large animal model in which to explore laryngological research questions, such as those relating to laryngeal transplantation, we investigated the normal mucosal immunology of the porcine larynx. Pig larynges and tracheae were processed and prepared for bright-field microscopy and quantitative, multiple-colour immunofluorescence histology using pig-specific monoclonal antibodies. There was an abundance of immunologically active cells within the mucosa of the larynx and trachea of both the newborn and adult animal. Specifically, major histocompatibility complex class II (MHC class II+) cells, CD4+ and CD8+ cells were identified, although regional differences in numbers were apparent: specifically, the supraglottis contained fewer immunologically relevant cells than other sites sampled. There was a significant correlation between the numbers of MHC class II+ and CD4+ cells indicating co-ordinate regulation and therefore functional local interactions. The presence of such an immunological structure suggests that the larynx may have important functions in respiratory immunology and that it may trigger strong alloresponses after laryngeal transplantation.