Delayed Diagnosis of Cystic Fibrosis and Nontuberculous Mycobacterial Infection in Refractory CRSwNP.

Cystic fibrosis is a systemic disease inherited in an autosomal recessive pattern associated with multisystem pathology including increased mucus viscosity and consequently reduced clearance. Here we report a case of a 31 year old woman who experienced several years of treatment-resistant type 2 low chronic rhinosinusitis. Repeat chest imaging revealed tree-in-bud change leading to a diagnosis of Mycobacterium abscessus and ultimately cystic fibrosis. She experienced a significant improvement following condensing M. abscessus eradication therapy and Kaftrio. This case outlines the importance of both considering atypical infection in treatment-resistant chronic rhinosinusitis and the underlying pathology such as cystic fibrosis.