Right Middle Lobe Syndrome Clinical Presentation
- Author: Nemr S Eid, MD, FAAP, FCCP; Chief Editor: Michael R Bye, MD more...
The most common symptoms in right middle lobe syndrome (RMLS) include the following:
- Persistent or recurrent cough
- Intermittent wheezing
- History of recurrent or chronic pneumonia (May often be a misinterpretation of the radiographic findings)
In many cases, these respiratory symptoms are refractory to normal treatment.
At least half of the patients report a history of asthma or atopy, and one third report a family history of atopy.
Less frequently reported symptoms, which may be indicative of chronic disease with suppurative complications, include the following:
- Low-grade fever
- Weight loss
- Chest pain
Right middle lobe syndrome is essentially a radiographic diagnosis, and physical findings widely vary.
Auscultation of the lungs may reveal a fine wheeze, rales, or diffuse rhonchi, ranging from decreased aeration and dullness to percussion in the region of the right middle lobe. The right middle lobe is anterior, best heard at the nipple. The medial segment is located medial to the nipple; the lateral segment is lateral to the nipple. Failure to listen to this area results in failure to hear the right middle lobe.
Clubbing is rarely found in patients with advanced disease.
In children, right middle lobe syndrome is usually secondary to primary ventilation disorders. Chronic inflammation of the airways, which contributes to atelectasis of the right middle lobe, is present. A paucity of collateral ventilation is observed in children and serves to prevent reinflation.
Primary disorders of ventilation include the following:
- Chronic pneumonia or bronchitis
- Other chronic lung diseases caused by aspiration or gastroesophageal reflux
- Primary ciliary dyskinesia (immotile cilia syndrome
Airway foreign body aspiration include the following:
- Endobronchial tumors
- Mucous plugging, as from any of the above
- Granulation tissue
Extraluminal compression is caused by the following:
- Cardiovascular anomalies
- Congenital malformations such as situs inversus and other anatomical defects such as anomalous branching or abnormal diameter, length, or structure of the bronchi
- Lymphadenopathy of peribronchial nodes
- Traction diverticula of the esophagus
See the list below:
- Whether the infection is a cause of the collapse or a result of airway stasis and poor clearance may not be clear.
- Primary infectious etiology is more frequent in adults; however, one pediatric study found that 50% of children with collapsed right middle lobe had an underlying bacterial infection.
- Infectious causes also increase in frequency among immunocompromised patients.
- Fungal causes include histoplasmosis, blastomycosis, and aspergillosis, which manifest as allergic bronchopulmonary aspergillosis (APBA).
- Mycobacteria, including Mycobacterium tuberculosis, Mycobacterium avium-intracellulare, and Mycobacterium fortuitum have also been identified as causal agents.
- Occurrence is mainly caused by extrinsic compression by hilar lymph nodes, which are commonly observed in these infections as well as in fungal infections.
Springer C, Avital A, Noviski N, et al. Role of infection in the middle lobe syndrome in asthma. Arch Dis Child. 1992 May. 67(5):592-4. [Medline].
Liu J, Chen SW, Liu F, Li QP, Kong XY, Feng ZC. The diagnosis of neonatal pulmonary atelectasis using lung ultrasonography. Chest. 2015 Apr 1. 147(4):1013-9. [Medline].
[Guideline] Institute for Clinical Systems Improvement (ICSI). Diagnosis and management of asthma. 2008 Jan. [Full Text].
Priftis KN, Mermiri D, Papadopoulou A, et al. The role of timely intervention in middle lobe syndrome in children. Chest. 2005 Oct. 128(4):2504-10. [Medline].
Halliday HL, Ehrenkranz RA, Doyle LW. Early (< 8 days) postnatal corticosteroids for preventing chronic lung disease in preterm infants. Cochrane Database Syst Rev. 2009 Jan 21. CD001146. [Medline].
Brown M, Lemen R. Bronchiectasis. Kendig's Disorders of the Respiratory Tract in Children. Philadelphia, Pa: WB Saunders Co; 1998. 150-2.
Priftis KN, Anthracopoulos MB, Mermiri D, et al. Bronchial hyperresponsiveness, atopy, and bronchoalveolar lavage eosinophils in persistent middle lobe syndrome. Pediatr Pulmonol. 2006 Sep. 41(9):805-11. [Medline].
Torkian B, Kanthan R, Burbridge B. Diagnostic pitfalls in fine needle aspiration of solitary pulmonary nodules: two cases with radio-cyto-histological correlation. BMC Pulm Med. 2003 Sep 8. 3(1):2. [Medline]. [Full Text].