Left pulmonary aplasia with left pulmonary artery agenesis in a child: case report from Nepal

Abstract

Background

Unilateral pulmonary agenesis is a rare congenital anomaly with an incidence of 1:15,000, affecting both sides and sexes equally. It's classified by Schneider-Schwalbe (Types 1–3) and Boyden systems (Groups 1–3) based on developmental severity. Children commonly experience recurrent respiratory tract infections and breathing difficulties due to aberrant tracheal function and increased vulnerability from airway constriction.

Case presentation

A 9-year-old male presented with fever and nonproductive cough. Physical examination revealed severe malnutrition (weight and BMI < -3Z score) with tracheal deviation, decreased left chest movement, dullness to percussion, and diminished breath sounds on the left side. Chest X-ray showed complete left hemithorax opacification with mediastinal shift. High-resolution computed tomography revealed left lung aplasia with compensatory right lung hyperinflation. Computed tomography pulmonary angiogram (CTPA) confirmed left pulmonary artery agenesis. Bronchoscopy demonstrated hypoplastic left bronchial tree with blind-ending left main bronchus and tracheal bronchus supplying the right upper lobe. The patient was treated with antibiotics for secondary infection, chest physiotherapy, inhaled corticosteroids, and nutritional support.

Conclusion

This rare congenital anomaly highlights the importance of advanced imaging in diagnosing complex respiratory presentations in pediatric patients with recurrent respiratory infections.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-025-06487-7.

Background

Unilateral pulmonary agenesis is a rare congenital anomaly with estimated incidence of 1:15,000 as per data from autopsy [1]. Occurrence is usually sporadic, but parental consanguinity has also been reported [1, 2]. There is no side predilection for occurrence of lung aplasia [1]. Both hemi thoraces and both genders are affected almost equally [3].

In 1912, Schneider and Schwalbe et.al classified the condition as Type 1 (agenesis) when the carina, main bronchus, lung tissue, and pulmonary vasculature are completely absent; Type 2 (aplasia) when the carina and a rudimentary bronchus are present, but when no alveolar tissue and pulmonary vessels exist on the affected side; and Type 3 (hypoplasia) when deformed bronchi and a reduced amount of lung tissue are present [4]. Boyden et al. in 1955classified the condition in a more practicable application based on the degree of developmental arrest, viz. group 1 complete absence of one or both lungs (agenesis); group 2 suppression of all but a rudimentary bronchus (aplasia); and group 3 abortive growth (hypoplasia) [5]. Additional malformations are found in more than 50% of the patients, mainly involving the cardiovascular, gastrointestinal, and musculoskeletal systems. Defects involving the musculoskeletal system are usually ipsilateral to the pulmonary agenesis [6]. Embryologically, pulmonary agenesis results from failure of development of the lung bud during the fourth week of gestation. The prognosis varies significantly based on the presence of associated anomalies. Isolated unilateral pulmonary agenesis has a survival rate of approximately 50%, while cases with associated cardiac or skeletal anomalies have considerably poorer outcomes [7].

Recurrent respiratory tract infections or breathing difficulties are common in children with this disease. Their increased vulnerability to lung infections could be the consequence of aberrant tracheal function brought on by the airway's constriction and stretching as the surrounding chest structures move [8].

We present a case of left pulmonary aplasia (Schneider-Schwalbe Type 2) accompanied by left pulmonary artery agenesis, diagnosed at the age of 9 years. Based on Boyden's classification, this aligns with Group 2, where a primitive bronchus exists without lung tissue or pulmonary blood vessels.

Case presentation

A 9 years-old-male, previously healthy with complete immunization, without significant family history, was brought with complaints of fever for 3 days which was acute in onset, continuous and documented as 103 °F; was not associated with chills or rigor. It was also associated with cough for 3 days, which was acute, 10–12 episodes per day of 2–3 bouts per episode, nonproductive, without diurnal or postural variation. No history of post tussive vomiting, cyanosis, fast breathing or chest retraction, chest pain, shortness of breath, rashes, anorexia, night sweats or weight loss. Mother reported history of recurrent upper respiratory tract infections (URTI) occurring approximately 3–4 times per year since age 2 years, with previous hospitalization for lower respiratory tract infection (pneumonia) at age 2 years at other center, however, documentation was unavailable and further work-up for the case was refused at that time. Antenatal history was unremarkable with normal full-term delivery.

On examination, general condition of the child was fair and vitals were stable. Anthropometric assessment using CDC growth charts showed: weight 15 kg (weight-for-age < −3Z score), height 115 cm (height-for-age < −2 Z score), and BMI 11.3 kg/m² (BMI-for-age < −3Z score), indicating severe acute malnutrition [9]. General physical examination was normal with no clubbing or cyanosis. Systemic examination revealed normal per abdominal, cardiovascular and central nervous system findings. However respiratory system examination revealed slightly right sided deviation of trachea, decreased chest movement of left hemithorax, dull note on percussion over left side of chest and bronchial breath sounds prominent over clavicular and mammary region and decreased air entry over remainder lung areas of left side, with vesicular breath sounds over right chest (Table 1).

Table 1.

Hematological, biochemical, and microbiological investigation results

Parameters	Findings
Hemoglobin	12.9 g/dL
Total Leucocyte Count	6800/mm3
Differential Leucocyte Count	Neutrophils 55, Lymphocytes 37, Monocytes 6, Eosinophils 2
Packed Cell Volume	38.7%
Platelet count	288,000/mm3
Alanine Aminotransferase/Aspartate Aminotransferase/Alkaline Phosphatase	17.1/37.7/526 IU/L
Creatinine	0.25 mg/dL
Urea	37.4 mg/dL
Sodium	134 mEq/L
Potassium	4.13 mEq/L
Human Immunodeficiency Virus I&II antibody/Hepatitis B surface Antigen/Hepatitis C Virus antibody test	Non-reactive on immunochromatography
C-Reactive Protein (quantitative)	14.24 (Positive)
Acid Fast Bacilli I & II	No acid-fast bacilli seen
Sputum GeneXpert	Negative for mycobacterium tuberculosis

Xray chest (Fig. 1) showed opaque left hemithorax with mediastinal shift to ipsilateral side with rib crowding and elevated left hemidiaphragm s/o collapsed left lung.

Fig. 1.

Chest X-ray (PA view) showing complete opacification of left hemithorax with mediastinal shift to ipsilateral side, rib crowding, and elevated left hemidiaphragm

Ultrasonography of chest (Fig. 2) showed minimal free fluid in left pleural space. Right pleural space was unremarkable.

Fig. 2.

Ultrasonography of chest showing minimal pleural fluid in left hemithorax (in between two + sign)

Electrocardiogram showed low voltage normal waves with clockwise rotation of the heart.

Echocardiography showed abdominal situs solitus, levocardia with normal segmental analysis with left sided aortic arch with trace Mitral regurgitation with mild tricuspid regurgitation with normal pulmonary artery pressure, left pulmonary artery could not be visualized.

High Resolution Computer Tomography (HRCT) chest (Fig. 3A) shows tracheal bronchus arising from right lateral wall of trachea supplying right upper lobe, with short rudimentary blind ending left main bronchus with complete absence of left lung, compensatory hyperinflation and herniation of right lung into the contralateral side anteriorly and posteriorly, with ipsilateral shift of mediastinum to left hemithorax, with unremarkable right lung parenchyma. CT Pulmonary angiogram (Fig. 3B) showed normal opacification of main pulmonary artery and its right branches with absence of left pulmonary artery s/o left pulmonary artery agenesis.

Fig. 3.

A High-resolution computed tomography chest showing left lung aplasia with compensatory right lung hyperinflation and herniation, and trancheal bronchus showing left lung aplasia with compensatory right lung hyperinflation and herniation, and trancheal bronchus. B CT pulmonary angiogram showing absence of left pulmonary artery with normal right pulmonary artery branches

Bronchoscopy showed hypoplasia of left bronchial tree with blind ending proximal segment of left main bronchus with secretions s/o left lung aplasia with tracheal bronchus (Fig. 4).

Fig. 4.

Bronchoscopy image showing hypoplastic left bronchial tree with blind-ending proximal left main bronchus

Thorough examination revealed no extra-pulmonary manifestations.

Child was admitted with provisional diagnosis of right sided community acquired pneumonia and was started on oral flucloxacillin at 250 mg QID and cefpodoxime at 100 mg BD for seven days and patient became afebrile after 48 h of antibiotics. Oxygen supplementation was not required as no signs of respiratory distress or hypoxemia was present. Though chest findings and severe wasting pointed towards diagnosis of pulmonary tuberculosis, it was ruled out as Mantoux showed no induration and sputum AFB/Sputum GeneXpert showed negative for Mycobacterium tuberculosis. No variability in PEFR with short acting bronchodilator (salbutamol 400 µg). Patient was further evaluated with USG chest which was suggestive of lung collapse. HRCT chest revealed lung aplasia, then Computed Tomography Pulmonary Angiogram (CTPA) was done which showed agenesis of left pulmonary artery. Pulmonology consultation advised for bronchoscopy which was suggestive of left lung aplasia with tracheal bronchus.

Management strategies for pulmonary agenesis include conservative approaches focusing on prevention and early treatment of respiratory infections, immunization including pneumococcal and influenza vaccines, pulmonary physiotherapy, and nutritional optimization. Long-term monitoring involves regular pulmonary function assessment, growth monitoring, and screening for complications such as scoliosis and pulmonary hypertension in the remaining lung. Prognosis depends on presence of associated anomalies; isolated cases have survival rates approaching 70–80% with appropriate management, while those with significant cardiac anomalies have considerably worse outcomes [7]. Our patient is on regular 3-monthly follow-up with multidisciplinary team involvement. Patient was started on chest physiotherapy and inhaled corticosteroid (Budesonide MDI,100 µg) with inhaled short-acting beta-2 agonist (Salbutamol MDI,100 µg) was given during hospital stay for symptomatic relief and suggested for continuation after discharge at home. Patient was consulted with nutritionist, and tailored dietary therapy was done. Following the treatment, patient improved clinically and was discharged with advice to follow up 3 monthly.

Discussion

Pulmonary agenesis is a rare congenital anomaly characterized by the complete absence of lung tissue, bronchi, and pulmonary vasculature on one side. Left-sided pulmonary agenesis is less common than right-sided agenesis but presents with significant clinical challenges, including recurrent respiratory infections, compensatory emphysema of the contralateral lung, and possible associated cardiac or skeletal anomalies [4].

Our patient presented with URTIs, a common complication in pulmonary agenesis due to the reduced respiratory reserve and impaired mucociliary clearance in the remaining lung. The absence of the left lung leads to compensatory hyperinflation of the right lung, which may predispose to infections due to mechanical inefficiency and chronic bronchial irritation [10]. Additionally, the mediastinal shift can cause tracheal compression, further exacerbating respiratory symptoms [11]. Various case reports mentioned that unilateral pulmonary agenesis involves complete absence of one lung without a pleural cavity, with left-sided agenesis having better prognosis than right-sided [3]. Over 50% have associated cardiac or airway anomalies, and while compatible with life when isolated, severe respiratory infections in infancy commonly lead to pneumonia and potential mortality [12]. The association between pulmonary agenesis and recurrent infections has been documented in previous case reports. A study by Mardini & Nyhan reported that children with unilateral pulmonary agenesis often experience frequent respiratory infections due to the remaining lung's increased workload and susceptibility to bronchial obstruction [13]. Maltz & Nadas et al. also reported frequent recurrence of URTIs and pneumonia in patients with pulmonary agenesis, requiring close monitoring and prophylactic therapy [3].

Management of recurrent URTIs in pulmonary agenesis includes treatment of infections, immunization (including pneumococcal and influenza vaccines), and pulmonary hygiene techniques to prevent mucus accumulation [14]. In some cases, long-term antibiotic prophylaxis or bronchodilators may be considered, however, we only used bronchodilators for long-term in our case [14, 15].

Furthermore, in our case, the patient showed marked acute malnutrition, likely caused by recurrent respiratory infections that increased energy demands while illness-related anorexia reduced intake [16]. Malnutrition in pulmonary agenesis worsens respiratory muscle weakness, delays weaning from mechanical ventilation, and increases susceptibility to infections [17]. Early involvement of multidisciplinary teams (pediatrician, pulmonologist, radiologist, and dieticians) is critical to address the mixed challenges of respiratory and nutritional support which was done in our case. There was possibility of doing bronchoalveolar lavage in our setting which was missed as the bronchoscopy facility for children was not available in our center.

Conclusions

Our case was reported in age of 9 years with history of recurrent infections which necessitates early recognition and multidisciplinary management of pulmonary agenesis to reduce complications such as recurrent infections, which significantly impact quality of life. As per the history, patient’s parents refused further work-up at early age. Further studies are needed to establish early screening procedures and standardized guidelines for infection prevention as well as malnutrition in patients with congenital lesions of lungs.

Abbreviations

URTI

Upper Respiratory Tract Infection

HRCT

High-Resolution Computed Tomography

CTPA

Computed Tomography Pulmonary Angiogram

PEFR

Peak Expiratory Flow Rate

MDI

Metered Dose Inhaler

BMI

Body Mass Index

SD

Standard Deviation

USG

Ultrasonography

Authors’ contribution

Material preparation, data collection, and literature search were performed by Sushant Ghimire. The first draft of the manuscript was written by Sushant Ghimire, and all authors commented on previous versions of the manuscript. Sushant Ghimire, Sabin Acharya, Bishwo Raj Bahadur Kunwar and Umesh Kumar Singh provided diagnoses and treatments to the patients reported in this study. Sushant Ghimire and Anjan Khadka supervised the manuscript drafting. All authors have read and agreed to the published version of the manuscript.

Funding

No funding was done.

Data availability

No datasets were generated or analysed during the current study.

Declarations

Ethics approval and consent to participate

This study was approved by the Institutional Review Committee of Nepalese Army Institute of Health Sciences. Written informed consent to participate in this study was provided by the legal guardian of kin.

Consent for publication

Written informed consents were obtained from the parents and the participants for the publication of this study. The parents and the participants consented to the publication of the case and any accompanying images with written consent.

Competing interests

The authors declare no competing interests.