[A case of chronic rhinosinusitis with nasal polyp with comorbid respiratory epithelial adenomatoid hamartoma with poor response to biologics].

Objective

This paper reports a case of a male patient who complained about nasal congestion and loss of smell for 20 years. Physical examination revealed polyp-like masses in bilateral olfactory clefts and middle meatus. The patient was diagnosed with chronic rhinosinusitis with nasal polyps（CRSwNP） and exhibited poor response to an adequate course of topical intranasal corticosteroids, then he enrolled in two clinical trials using anti IL4-Rα and anti-TSLP monoclonal antibodies consequently. The treatment duration for each trial was 16 weeks, respectively. The size of his nasal polyps did not change, which was the main endpoint result for both clinical trials. Then the patient underwent an endoscopic surgery and the pathology was respiratory epithelial adenomatoid hamartoma（REAH）, which was further confirmed by the single cell sequencing results of the operative specimen, which were different from normal nasal polyps. The diagnosis of REAH is dependent on pathology and preoperative examination has limited specificity, and REAH may share similarities with nasal polyps. Therefore, REAH should be considered for the differential diagnosis when patients with polyp-like masses exhibit poor response to sufficient treatment using biologics.