Predictors and prognosis of respiratory epithelial adenomatoid hamartoma in sinonasal cavities

OBJECTIVE: Respiratory epithelial adenomatoid hamartoma (REAH) is classified as a histopathologic diagnosis and often identified in sinus surgery for chronic rhinosinusitis (CRS). The purpose of this study was to clarify the frequency and predictors of REAH and prognosis of CRS with REAH in CRS cases. METHODS: In the first study, we histologically reviewed sinonasal polyps and mucosal tissue specimens obtained from patients who underwent endoscopic sinus surgery (ESS) for CRS to reveal how many REAH were involved in ESS cases. We compared REAH and non‐REAH groups in terms of preoperative symptoms and endoscopic, imaging and blood examination findings to elucidate predictors of REAH genesis. In the second study, we compared the data 3 months after surgery such as endoscopic and imaging findings and olfactory test to evaluate prognosis of CRS with REAH. RESULTS: The prevalence of REAH was 15.5% of all 304 cases in the first and second studies combined. Higher polyp score in the middle meatus was an independent predictor of the presence of REAH (p = .02). Presence of REAH was significantly associated with the enlargement of olfactory cleft polyps (p < .01), increasing postoperative scores of standard olfactory tests (p = .03), and decline of ratio of improvement (p < .01) measured using T&T olfactometry. CONCLUSIONS: Higher polyp score in the middle meatus is an independent predictor of REAH. Olfactory function is difficult to recover after surgery in REAH patients because it is associated with recurrent polyps in the olfactory cleft.