Chronic Sinonasal Inflammation as a Comorbidity of Respiratory Epithelial Adenomatoid Hamartoma: A 15-Year Retrospective Observational Study

<b>Background:</b>Respiratory epithelial adenomatoid hamartoma (REAH) is a benign pseudo-glandular proliferation of the nasal cavity with poorly-understood etiopathogenesis. This study aimed to examine the frequency of comorbidities in patients with REAH and to determine whether comorbidity affects the clinical characteristics of REAH. <b>Methods:</b> A retrospective cohort study included patients with REAH treated at 2 university hospitals over 15 years. Clinical parameters included the side of the nasal cavity, localization and size of the lesion, duration of symptoms, follow-up period, and associated chronic inflammation. <b>Results:</b> Twenty previously-unoperated patients with REAH were included. We found an association of REAH with chronic sinonasal disorders in 70% of cases: in 30% with perennial allergic rhinitis (PAR), in 25% with chronic rhinosinusitis with nasal polyps (CRSwNP), and in 15% of cases with aspirin-exacerbated respiratory disease (AERD). In 87.5% of cases of bilateral REAH, the lesion was associated with NPs, in 80% of patients with CRSwNP as a comorbidity, and in 100% of patients where it was AERD. Symptoms were longer in REAH patients with associated sinonasal inflammation (<i>P</i> < .038). We found a far-greater average volume of REAH in patients with AERD than in cases with PAR, and CRSwNP (<i>P</i> < .001; <i>P</i> < .001, respectively) and a positive correlation between the duration of symptoms and the lesion volume (<i>R</i> = .700; <i>P</i> = .001). The follow-up period was longer in patients with comorbidities (<i>P</i> < .028), and recurrences of REAH were noted only in 2 patients with AERD as a comorbidity. <b>Conclusion:</b> A high degree of association between REAH and chronic sinonasal inflammation was found. Also, the results suggest that inflammation in AERD is the strongest provoking factor for the growth of REAH. A direct correlation was observed between the duration of nasal symptoms and the lesion size.