High attenuation mucoid impaction in allergic bronchopulmonary aspergillosis

Allergic bronchopulmonary aspergillosis (ABPA) is a complex hypersensitivity syndrome triggered against antigens of Aspergillus fumigatus, a fungus that most commonly colonizes the airways of patients with bronchial asthma and cystic fibrosis. It presents clinically with refractory asthma, hemoptysis and systemic manifestations including fever, malaise and weight loss. Radiologically, it presents with central bronchiectasis and recurrent episodes of mucus plugging. The mucus plugs in ABPA are generally hypodense but in up to 20% of patients the mucus can be hyperdense on computed tomography. This paper reviews the literature on the clinical significance of hyperattenuated mucus in patients with ABPA.