Unveiling the complexity of right middle lobe syndrome: a case series highlighting the association with asthma.

Introduction and importance: Right middle lobe syndrome (MLS) is a rare lung disorder primarily affecting children with a history of asthma or atopy. It encompasses a range of pathological and clinical conditions, from recurrent collapses of the middle lobe to bronchiectasis. In this study, the authors present a case series featuring four individuals with MLS associated with asthma, aiming to deepen our understanding of this uncommon condition. Case presentation: Four paediatric patients with right MLS exhibited symptoms of persistent cough, dyspnoea, and recurrent asthma exacerbations. Radiographic evaluations confirmed features consistent with right MLS, and bronchoscopy revealed mucus plugs and oedematous airways obstructing the right middle lobe bronchus. Treatment with bronchodilators, antibiotics, and corticosteroids led to symptom improvement and resolution of atelectasis. Clinical discussion: MLS is a rare condition characterized by chronic collapse of the right middle lobe and bronchiectasis. It is challenging to diagnose MLS, but computed tomography (CT) scans provide detailed lung images for confirmation. Treatment focuses on addressing the underlying cause, such as infections or mucus obstruction. Lobectomy may be considered in severe cases. This case series emphasizes the need for further research on MLS, as its rarity and characteristics remain unclear. Conclusion: These cases exhibited obstructive MLS with and without asthma. Accurate diagnosis is challenging, requiring imaging techniques. MLS has clinical implications, particularly in asthma patients. Future studies should focus on understanding the aetiology of non-obstructive MLS.