Aims: This study examined the frequency of comorbidities in patients with respiratory epithelial adenomatoid hamartoma (REAH) and determined whether comorbidity affects the clinical characteristics of REAH.

Methods: A retrospective cohort study included patients with REAH who had been treated and followed up over 15 years. Clinical parameters included the side of the nasal cavity, localization and size of the lesion, duration of symptoms, and associated chronic inflammation.

Results: Twenty (n = 20) patients with REAH were included. We found an association of REAH with chronic sinonasal inflammatory 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 inflammatory nasal polyps, in 80% of patients with CRSwNP as a comorbidity, and in 100% of patients when it was AERD. Symptoms were longer in REAH patients with associated sinonasal inflammation (P ˂ 0.038). We had a far greater average volume of REAH in patients with AERD than in cases with PAR, and CRSwNP (P ˂ 0.001; P ˂ .001, respectively). A positive correlation was found between the duration of symptoms and the lesion volume (R = 0.700; P = 0.001).

Conclusion: A high degree of association between REAH and chronic sinonasal inflammation was found. The results also 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.