Middle lobe syndrome in children today.

Middle lobe syndrome in children is a distinct clinical and radiographic entity that has been well described in the pediatric literature. However, issues regarding its etiology, clinical presentation, and management continue to puzzle the clinical practitioner. Pathophysiologically, there are two forms of middle lobe syndrome, namely obstructive and nonobstructive. Middle lobe syndrome may present as symptomatic or asymptomatic, as persistent or recurrent atelectasis, or as pneumonitis or bronchiectasis of the middle lobe and/or lingula. A lower threshold of performing a chest radiograph is warranted in children with persistent or recurrent nonspecific respiratory symptoms, particularly if there is clinical deterioration, in order to detect middle lobe syndrome and to initiate a further diagnostic and therapeutic workup.