Middle lobe syndrome: a rare presentation of allergic bronchopulmonary aspergillosis.

Allergic bronchopulmonary aspergillosis (ABPA) is a disease predominantly seen in susceptible asthmatic subjects, due to a hypersensitivity phenomenon caused by colonisation of the airways by Aspergillus species. Although collapse, both lobar and segmental due to mucoid impaction, is not uncommon in ABPA, a middle lobe syndrome (MLS) secondary to ABPA is rather an uncommon association. We report this rare and unusual clinical presentation in a 36-year-old male, who presented for evaluation of a "non resolving pneumonia". Imaging suggested the presence of a MLS and central bronchiectasis. Further investigations revealed that the patient met 6/8 of the essential diagnostic criteria for ABPA. Appropriate therapy with oral corticosteroids resulted in remarkable symptomatic improvement.