Incidental Diagnosis of Swyer-James-MacLeod Syndrome: A Case Report and Review of Literature

1. Assistant Professor, Department of Internal Medicine, Datta Meghe Institute of Medical Sciences, Nagpur, Maharashtra, India. 2. Associate Professor, Department of Respiratory Medicine, Datta Meghe Institute of Medical Sciences, Nagpur, Maharashtra, India. 3. Professor, Department of Internal Medicine, Datta Meghe Institute of Medical Sciences, Nagpur, Maharashtra, India. 4. Junior Resident, Department of Internal Medicine, Datta Meghe Institute of Medical Sciences, Nagpur, Maharashtra, India. 5. Junior Resident, Department of Internal Medicine, Datta Meghe Institute of Medical Sciences, Nagpur, Maharashtra, India.

Abstract

Swyer-James-MacLeod Syndrome (SJMS) appears as unilateral hyperlucency on chest imaging and is documented as a rare sequela of frequent paediatric respiratory infections. Due to its rarity, various causes of haemithoracic radio-opacity and radiolucency were studied while evaluating this case. In individuals with bronchiolitis obliterans, SJMS has been observed in about 4% of cases. The left lung is preferentially involved in most cases for unknown reasons. The syndrome usually develops following viral respiratory infection in infancy or early childhood, such as adenoviruses or Mycoplasma pneumoniae. It is predicted to have a prevalence of 0.01%. This case study focuses on an incidental finding of abnormal radiography identified during assessing a 54-year-old man with low back pain in Chronic Kidney Disease (CKD). Patient and relative should be explained about the Chest X-ray finding and the reason for SJMS to avoid unscrupulous investigations in the future as index patient had no respiratory symptoms.

Bronchiolitis obliterans, Diminished vascularity, Unilateral hyperlucent lung, Viral respiratory infection

Case Report

A 54-year-old man, averagely built, a retired cotton textile industry worker, presented to the Outpatient department with low back pain and radicular left lower limb pain [on a pain scale of 0-10, 0 being no pain and 10 as worst possible pain; he scored his current pain as 4/10] for one month. He was never on any treatment for the same. He did not give any history of cough, breathlessness, or haemoptysis. He was recently diagnosed with CKD (Serum creatinine: 2.32 mg/dL, urea: 45.79 mg/dL) with secondary hypertension and was not on any treatment.

On general examination, he had a pulse rate of 90 beats/min, regular, peripheral pulses were well felt and were synchronous, blood pressure of 150/90 mmHg, and BMI of 23 kg/m². He had mild pallor (Haemoglobin: 11 gm%). There was absence of cyanosis, clubbing, icterus, oedema, lymphadenopathy, and Jugular Venous Pulse (JVP) was not raised. On systemic examination, his respiratory system findings revealed reduced chest expansion (3 cm), normal Transverse: Anteroposterior ratio, chest movements were decreased on the left side compared to the right, hyper-resonant note on percussion, and decreased breath sounds on the left side. There were no adventitious breath sounds.

Initial evaluation showed an abnormal chest radiograph (expiratory film) with unilateral generalised lucency on the left side compared to the right side (Table/Fig 1). His inspiratory Chest X-ray (unrotated) was done (Table/Fig 2) which showed enhanced hyperlucency on the left side compared to earlier expiratory film. As he had no respiratory symptoms like shortness of breath, cough, pedal oedema and raised JVP. Due to financial constraints, Computed Tomography (CT) pulmonary angiography could not be done and was emphasised on regular follow-up and to visit the hospital if he experienced symptoms like acute shortness of breath, cough and haemoptysis. Bedside lung functions like single breath count and breath-holding capacity were within normal range. His Peak Expiratory Flow Rate (PEFR) was 450 litre/min. His Electrocardiogram was suggestive of the Left Bundle branch block and left ventricular hypertrophy (Table/Fig 3) and was a coincidental finding. His 2-Dimensional echocardiography was suggestive of concentric left ventricular hypertrophy, degenerative (calcific and sclerosed) aortic valve, and mild aortic regurgitation with normal left ventricular ejection fraction.

The patient had no respiratory symptoms and was incidentally diagnosed with SJMS, based on a chest radiograph. He was not further investigated for the syndrome and medically managed for the CKD and hypertension.

Discussion

SJMS is challenging to diagnose routinely because of its rarity. It happens because of an inflammatory reaction to a viral or bacterial infection in childhood which causes the affected lung area to develop abnormally, resulting in radiographic asymmetry. SJMS isn’t known to progress and isn’t linked to any systemic illnesses. In the present case, a middle-aged man whose chest radiograph was certainly abnormal at the time of admission had no prior respiratory complaints. Tuberculosis, pertussis (whooping cough), mycoplasma, and viral infections like a respiratory syncytial virus, adenovirus type 3, 7, 21, influenza A, measles, paramyxovirus morbillivirus, radiation therapy, and breathing in a foreign body have all been reported to cause SJMS in children (1),(2). Research suggests that a hyperimmune reaction in the lung (producing antibodies) may result in sustained airway damage following initial infection. A pre-existing lung defect may make people vulnerable to developing the disease. Even though bronchial injury during childhood is thought to be an important inciting factor, many affected do not have documented history of respiratory tract infection. Certain unknown variables present at birth probably have a role in SJMS development (3).

On radiographs, SJMS is known to cause a small lung with hyperlucency unilaterally and air trapping on expiration. The affected lung is hyperlucent and has decreased vascularity on CT scan and angiogram. The entire lung can be damaged, but there can also be lobar, segmental, and subsegmental involvement with a patchy distribution. The majority of the affected lobes are smaller, while they might rarely be normal size. In most cases, there is no anteroposterior attenuation of the gradient. Bronchiectasis may or may not be present (4). A tiny pulmonary artery with decreased vascularity in the periphery may be seen on Magnetic Resonance Angiography (MRA). A photopenic region is visible in the affected aspect of a quantitative ventilation/perfusion lung scan (1).

Differential diagnosis: Both congenital and acquired lung illnesses are included in the differential diagnosis (Table/Fig 4) (5),(6),(7).

One of the following is required as a diagnostic criterion for this syndrome (7):

1. Chest X-ray reveals a unilateral reduction of lung capacity with hyperlucency.
2. A computed tomography of the chest reveals a decrease in vascularity unilaterally.
3. There is a unilateral decrease of perfusion on a technetium Tc 99m lung scan.

To confirm the diagnosis, pulmonary angiography can be done to demonstrate decreased unilateral pulmonary vascularity, but in index case, because of lack of facility for pulmonary angiography, the patient was not advised the same and was advised for regular follow-up after explaining in detail about the condition and related risk including the development of recurrent respiratory tract infections and pneumothorax.

Treatment and prognosis: As the patient was asymptomatic, particularly for respiratory symptoms, and was incidentally diagnosed with SJMS, no further investigation was done for the incidental diagnosis of SJMS and medically managed his CKD and hypertension and advised for regular follow-up of every six months. The usual treatment is conservative and preventive to prevent lung infections. Inhaled corticosteroids could play a little role in therapy (1). Cases that present with complications are treated accordingly, those presenting with haemoptysis have been treated with pneumonectomy or lobectomy, or segmentectomy. Cases with Bronchiectasis are more vulnerable to respiratory infections. Bullae increase the risk of spontaneous pneumothorax. As a result of SJMS, a pulmonary abscess has also been recorded as a consequence (7).

Though the patient was a professional cotton mill industry worker, he was not heavily exposed to dust and so he never had any respiratory symptoms. On clinical examination, there was absence of clubbing, cyanosis, adventitious breath sounds which would have suggested Pneumoconiosis. Though he was diagnosed with CKD with secondary hypertension, pulmonary oedema was least likely as radiological changes were unilateral, there were absence of respiratory complaints, normal pulse oximetry, absence of oedema and adventitious breath sounds which led to the diagnosis of SJMS based on the radiological finding. Very few cases of adults with SJMS have been documented worldwide (Table/Fig 5) (8),(9),(10),(11),(12),(13),(14),(15).

Patient Counselling

Patient and the family should be explained about the chest X-ray finding along with the reason for SJMS to avoid unscrupulous investigations in further medical visits. Instructions should be given on recognising the early symptoms of respiratory infections. In case of acute respiratory distress, the patient should seek immediate medical attention to confirm the diagnosis of pneumothorax and any other complications.

Conclusion

SJMS is a rare entity that should have a high degree of suspicion if the patient is asymptomatic and with obvious chest X-ray and CT scan findings. The diagnosis is easily made using chest radiography (inspiratory and expiratory films) and CT, which shows a hyperlucent hemithorax on one side with decreased bronchovascular markings in the affected area of the lung. The main purpose of reporting this case was to avoid further unscrupulous and unwarranted investigations and treatment in such cases.

DOI and Others

DOI: 10.7860/JCDR/2022/57135.16937

Date of Submission: Apr 20, 2022
Date of Peer Review: May 18, 2022
Date of Acceptance: Aug 05, 2022
Date of Publishing: Sep 01, 2022

AUTHOR DECLARATION:
• Financial or Other Competing Interests: None
• Was informed consent obtained from the subjects involved in the study? Yes
• For any images presented appropriate consent has been obtained from the subjects. Yes

PLAGIARISM CHECKING METHODS:
• Plagiarism X-checker: Apr 28, 2022
• Manual Googling: Jul 16, 2022
• iThenticate Software: Aug 03, 2022 (8%)

ETYMOLOGY: Author Origin