Challenge of identifying a case of chronic invasive rhinosinusitis due to Rasamsonia aegroticola

Fungal rhinosinusitis are frequently described in humans and its prevalence appears to be increasing. They mainly involve species of the genus Aspergillus. To date, conventional mycological diagnosis remains challenging, as only 30% and 50% of cultures are positive in cases of fungal balls and invasive rhinosinusitis respectively. Over the past decade, human infections due to the Rasamsonia argillacea species complex are increasingly frequent and mainly concern patients with cystic fibrosis or chronic granulomatous disease. We report here the first case of pseudotumoral R. aegroticola sinusitis in a 66-year-old man with Meniere's disease requiring repeated corticosteroid cures. The CT scan revealed areas of condensation and thinning of the straight sphenoidal bone walls, whose bone lysis could be confirmed during surgical excision. Direct microscopic examination of samples from different culture media revealed sterile mycelium without fruiting bodies, and was therefore not contributive. However, the sequencing of ITS and β-tubulin regions, performed from mucosal fragments and sterile mycelium, allowed the identification of R. aegroticola.