Allergic Bronchopulmonary Aspergillosis Mimicking Lung Cancer: A Case Report.

Patients with allergic bronchopulmonary aspergillosis (ABPA), a hypersensitivity reaction to Aspergillus fumigatus, typically present with asthma; the common imaging findings are central bronchiectasis, mucoid impaction, and tree-in-bud opacities. In this report, we discuss the case of a heavy smoker who presented with a large pulmonary mass that was initially presumed to be primary lung cancer and who was ultimately diagnosed with ABPA, which responded favorably to steroid treatment.