Pathogenesis of Nasal Polyposis: Current Trends.

Chronic Rhinosinusitis (CRS) is characterized by edema of the sub-epithelial layers, but, only specific types of CRS are developing polyps. Nasal polyposis may develop under different pathogenetic mechanisms rendering the typical macroscopic classification of CRS, with or without nasal polyps, rather deficient. Currently, we approach nasal polyposis, in terms of diagnosis and treatment, according to its endotype, which means that we focus on the specific cells and cytokines that are participating in its pathogenesis. It appears that the molecular procedures that contribute to polyp formation, initiating with a Th-2 response of the adaptive immune system, are local phenomena occurring in the sub-epithelial layers of the mucosa. Several hypotheses are trying to approach the etiology that drives the immune response towards Th-2 type. Extrinsic factors, like fungi, Staphylococcus superantigens, biofilms, and altered microbiome can contribute to a modified and intense local reaction of the immune system. Some hypotheses based on intrinsic factors like the elimination of Treg lymphocytes, low local vitamin-D levels, high levels of leukotrienes, epithelial to mesenchymal transition (EMT) induced by hypoxia, and altered levels of NO, add pieces to the puzzle of the pathogenesis of nasal polyposis. Currently, the most complete theory is that of epithelial immune barrier dysfunction. Intrinsic and extrinsic conditions can damage the epithelial barrier rendering sub-epithelial layers more vulnerable to invasion by pathogens that trigger a Th-2 response of the adaptive immune system. Th2 cytokines, subsequently, induce the accumulation of eosinophils and IgE together with the remodeling of the stroma in the sub-epithelial layers leading, eventually, to the formation of nasal polyps.

Hamartomatous polyp of the palatine tonsil: histological considerations and review of the literature.

The hamartomatous polyp is a rare benign hamartoma of the palatine tonsil, usually encountered during the second decade of life. It may be reported under various terms in the literature, like lymphangioma of the tonsil, angiofibrolipoma, lymphangiomatous tonsillar polyp and lymphangiectatic fibrous polyp. Macroscopically, it appears as a large, pale, pedunculated mass. Typically, a hamartomatous polyp is asymptomatic or manifests mild symptoms, like foreign body sensation. It is not related to a generalised lymphatic malformation process. Despite its typical appearance, an excisional biopsy is necessary to rule out a malignancy. Histological findings are consistent with a squamous epithelial covering, a core of loose fibrous and adipose tissue with sparse lymphoid aggregations and dilated lymphatic channels filled with lymph and lymphocytes. Several embryologically based theories suggested its pathogenesis; however, recurrent tonsillitis does not play an established role. A typical tonsillectomy is suggested as a sufficient therapeutical approach with no tendency for recurrence.

The Eustachian Tube Dysfunction in Children: Anatomical Considerations and Current Trends in Invasive Therapeutic Approaches.

The eustachian tube (ET) has a crucial role in the physiology of the middle ear. Thus, any condition that renders the tube dysfunctional is directly implicated with middle ear pathophysiology, like in the case of acute otitis media and otitis media with effusion. Children are more vulnerable to pathologies of the middle ear, primarily due to the immature development of their eustachian tubes. Otitis media with effusion, apart from being a burden for hearing, with direct consequences for speech development, may also be implicated in cholesteatoma formation. Medical therapy is not practically effective for the treatment of effusion. Moreover, the established surgical approaches, like grommets and adenoidectomy, deal only indirectly with the problem since they are not addressing the dysfunctional ET itself. An emerging interventional approach that intends to restore the function of the tube is the transnasal balloon dilation of the cartilaginous part of the ET. Growing international experience indicates that this promising technique is safe and effective. In the current review, we aim to provide background information on the anatomy, physiology, and pathophysiology of the ET and to present the progress of the balloon dilation technique with emphasis on pediatric patients.