Constricted breath: a successfully managed case of sarcoidosis-associated endoluminal stenosis of proximal bronchi (ESPB)

To the Editor,

Sarcoidosis is a multisystem granulomatous disease of unknown cause that is characterized by the formation of non-caseous epithelioid cell granulomas. It affects mostly the 25- to 50-year-old age group and predominantly involves the lung and lymphatic system [1]. Sarcoidosis causes granulomatous inflammation of the airway and can involve the entire spectrum of airways from nasal and oral passage to the terminal bronchiole. Though airway involvement of sarcoidosis is common, endoluminal stenosis of proximal bronchi (ESPB) is quite rare with a retrospective study demonstrating ESPB in only 18 (0.7%) of 2500 sarcoidosis patients [2]. The medical literature regarding ESPB in sarcoidosis is restricted to case reports and the best of our knowledge there are no reported cases in the Indian population. We herein want to report a successfully managed case of sarcoidosis-associated ESPB in a young male patient.

A 31-year-old male patient was diagnosed case of pulmonary sarcoidosis (the basis of diagnosis was histopathological) and was on a tablet of prednisolone 10 mg once daily for the last 6 months. He presented to our center with complaints of increased breathlessness on exertion for a 1-month duration. On evaluation his vitals were normal. General and systemic examination were essentially normal with normal lung sounds and cardiac sounds on auscultation. His hematological and serum biochemical parameters were within normal limits. High-resolution computed tomography (HRCT) chest taken revealed concentric wall thickening of left main stem bronchi (Fig. 1). There were sub pleural linear interstitial changes and a few thin pleuroparenchymal bands noted involving anterior segment of right upper lobe anterior and lingular segment of left upper lobe and basal segments of both lower lobes with no significant mediastinal lymphadenopathy. Video bronchoscopy showed chinking of the left main bronchus with erythematous airway mucosa (Fig. 2). In view of sarcoidosis with significant endobronchial involvement causing narrowing of large airways, he was started on Tab prednisolone 60 mg once daily (1 mg/kg/day). The patient was reviewed after 4 weeks wherein he reported symptom resolution. Repeat bronchoscopy showed significant improvement in left main bronchus luminal narrowing and airway erythema (Fig. 3). Prednisolone was tapered at a rate of 10 mg every 2 weeks and tablet mycophenolate mofetil was added. On follow-up at 12 weeks patient had sustained symptom relief.

Fig. 1

HRCT chest lung window images in axial (a), coronal (b), sagittal (c) reformats and 3D virtual reconstruction (d) of trachea and bronchi in left oblique view showing antero-posterior narrowing of the left main bronchus (blue arrows). Note the consequent area of air trapping in the left upper lobe (a) (orange arrow)

Fig. 2

a Bronchoscopy showing erythematous mucosa, widened carina, and narrowed left main bronchus. b Bronchoscopy view of narrowed left main bronchus

Fig. 3

a Bronchoscopy repeated after 4 weeks of steroid therapy showing resolution of airway erythema. b Significant improvement in left main bronchus luminal narrowing after 4 weeks of prednisolone therapy

The involvement of airways in sarcoidosis is diverse with the spectrum consisting of mucosal erythema, granular mucosa, cobblestone mucosa, mucosal plaque, mucosal nodules, bronchial stenosis, bronchiectasis, bronchiolitis, extrinsic compression of airways, airway hyperreactivity, obstructive sleep apnea, and supraglottic airway involvement [1]. Airway obstruction in sarcoidosis is reported in as high as 65% of cases but this airway obstruction is predominantly due to small airway involvement [3]. ESPB is a rare manifestation of sarcoidosis characterized by narrowing of the proximal airway. The pathophysiological mechanism involves airway inflammation, granulomatous infiltration, and submucosal edema [2]. The symptoms include cough, dyspnea, wheezing, and rarely hemoptysis. Chest radiography is usually non-diagnostic while CT chest can demonstrate proximal airway narrowing. Bronchoscopy is diagnostic and can reveal airway narrowing, mucosal erythema, and “cobblestone” mucosa. Pulmonary function tests can demonstrate obstruction with a flow volume loop showing fixed airway obstruction [4]. Our patient was diagnosed based on radiological and bronchoscopy findings. As he was already diagnosed with sarcoidosis and was on low-dose steroids, a repeat biopsy was not taken from the airway. Spirometry was not done for the patient as it had no role in diagnosis. Being a rare disease the management of ESPB is mainly based on case report experiences. Corticosteroids remain the most used treatment with case reports showing both improvement and non-improvement with therapy. Studies have shown early initiation of steroids (within 3 months) to be beneficial while a delay in steroid therapy can cause a decrease in therapeutic response [2]. Our patient was initiated on steroid therapy soon after diagnosis and showed excellent response to therapy thereby avoiding the need for mechanical dilation of airway. This adds to the frugal literature evidence in the management of sarcoidosis-associated ESPB.