Does lymphatic obstruction play a role in the pathogenesis of antrochoanal polyps?

Objectives: Antrochoanal polyps (ACPs) originate from the inner wall of the maxillary. Most authors who have studied the icrostructure of ACPs, have not examined the transitional area between the sinus mucosa and the pedicle of the polyp. No explanation has been given for the absence of a cystic intrasinus portion of the polyp. The cystic intrasinus portion of the polyp is a cornerstone of the pathophysiology of ACPs, whether caused by inflammation, cicatrization, or allergy. This finding prompted us to examine the transitional area between the sinus mucosa and the pedicle of the polyp to verify the possibility that lymphatic obstruction - whether primary or secondary(cicatrization or inflammation) - could be an etiologic factor in the formation of ACPs.Methods: The study material consisted of 25 ACPs and 25 chronic maxillary sinusitis mucosal biopsy specimens (control group). The detection of lymphatic vessels was based on the identification of lymph vessel endothelial hyaluronic acid receptor 1 (LYVE-1) in the endothelial cells of the lymphatic capillaries. This was the first lymph-specific hyaluronic acid receptor to be characterized,differentiating them from (blood) capillaries.Results: The density of the lymphatic vessels was marked in 22 of the 25 ACP specimens 88% of the ACP cases,compared with 16% of the control group.Conclusions: This study demostrated the markedly high density of lymphatic vessels in the transitional area between the sinus mucosa and the pedicle of the ACPs, in comparison with the density in the control group. This finding refutes the "blocked acinus theory" and indicate that lymphatic obstruction, whether primary or secondary might play a leading role in the formation and further growth of ACPs.Der Erstautor gibt keinen Interessenkonflikt an