Serum and Tissue Periostin Expression in Unilateral Benign Lesions of the Nose and the Paranasal Sinuses

<b>Background/Objectives</b>: Periostin's role in the pathogenesis of inflammatory diseases, particularly in the nose and paranasal sinuses, is an area of growing interest. This study aims to evaluate the expression of periostin in mucoceles, inverted papillomas, choanopolyps and retention cysts. <b>Methods</b>: Tissue samples collected during functional endoscopic sinus surgery (FESS) were analyzed for POSTN gene mRNA expression using qPCR. Periostin protein levels were measured via ELISA and Western Blot. Serum periostin levels were also assessed through ELISA in both patients (<i>n</i> = 54) and controls (<i>n</i> = 12). <b>Results</b>: A total of 66 participants were recruited, including 18 with inverted papillomas, 10 with mucoceles, 10 with choanopolyps, 16 with retention cysts and 12 controls. There were no significant alternations between tissue and serum samples of inverted papilloma compared to the control group. Choanopolyp tissues exhibited elevated POSTN protein expression, though POSTN mRNA and serum levels remained unchanged. In mucoceles, periostin levels were significantly elevated in both tissues and serum. Retention cyst tissues demonstrated an increase in POSTN mRNA and protein expression, whereas serum periostin levels remained consistent with those observed in the control group. <b>Conclusions</b>: The findings suggest that periostin may play a role in the pathophysiology of benign non-neoplastic lesions of the nose and paranasal sinuses such as mucoceles, retention cysts and choanopolyps, highlighting a need for more investigation in this subject.