Clinico-radiological Approach in Diagnosis

A 27-year-old young female, hailing from Bardhaman district of West Bengal, with no known comorbidities presented to the outpatient department with a history of shortness of breath on exertion and cough with occasional expectoration for the past 3 years which worsened over the past 1 month. She also complained of frequent sneezing and runny nose. There was no history of fever, chest pain, hemoptysis, or loss of appetite. She had a past history of sputum-positive pulmonary tuberculosis in 2020 and had taken 6 months of antituberculosis therapy. On examination, she was alert, hemodynamically stable, and saturating well in room air. Scattered wheeze was heard over the left hemithorax. Routine blood investigations were within normal limits. Chest X-ray and computed tomography (CT) of the patient has been given below. Question Identify the radiological abnormality in the CT chest and the most probable cause for it. Answers Chest X-ray [Figure 1] shows clear lung fields. Figure 2 shows CT chest axial view with narrowed trachea. Figure 3 shows CT chest axial view with narrowed left main bronchus (LMB). Figure 4 shows CT chest axial view with left lingular atelectasis. Left lung parenchyma is hyperlucent The most probable cause is posttuberculosis tracheobronchial stenosis. On further evaluation, bronchoscopy was done which showed narrowing at the proximal LMB with inability to pass the scope [Figure 5].Figure 1: Chest Xray showing clear lung fieldsFigure 2: CT chest axial view with narrowed tracheaFigure 3: CT chest axial view with narrowed left main bronchus (LMB)Figure 4: CT chest axial view with left lingular atelectasisFigure 5: Fiber-optic bronchoscopic finding showing stenosis of the left main bronchiGraded hydrostatic balloon dilation of the left main bronchi was carried out. The postprocedure period was uneventful. Discussion Tracheobronchial stenosis refers to focal or diffuse narrowing of the trachea and bronchi which may arise from neoplastic or nonneoplastic processes. It may be focal, as in postintubation tracheal stenosis or from a tumor. Diffuse narrowing may arise from inflammatory diseases including tuberculosis infection.[1,2] Posttuberculosis tracheobronchial stenosis is the leading cause of nonneoplastic tracheobronchial stenosis and occurs as a long-term sequela in 11%–42% of patients.[3-5] It develops as a result of healing of mucosal necrosis of airways which eventually results in its fibrosis and stenosis.[6] Around 68% of patients with tracheobronchial TB may develop some degree of stenosis at 4–6 months, which may increase up to 90%, beyond this initial time period.[7] This may cause significant obstruction to the airways which results in recurrent infections, pulmonary function derangement, and severe limitation in the exercise capacity. LMB is more frequently involved than right main bronchus or trachea.[6,8] This is due to its anatomy where LMB is compressed between the aortic arch and the left mediastinal lymph nodes.[6] The bronchoscopic interventions are balloon dilatation alone, stent placement following balloon dilatation, laser photocoagulation, argon plasma coagulation, and cryotherapy which can offer immediate symptomatic relief.[6,9,10] Nevertheless, these methods have a high recurrence rate of stenosis. Surgical correction is considered when medical therapy and bronchoscopic interventional methods fail.[6] The extent of surgery may vary from tracheal resection and anastomosis, bronchoplastic procedures, bronchial sleeve resection, sleeve lobectomy to pneumonectomy.[6] Declaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given her consent for her images and other clinical information to be reported in the journal. The patient understands that her name and initials will not be published and due efforts will be made to conceal her identity, but anonymity cannot be guaranteed. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.