A rare cause of airway obstruction: Mediastinal cyst secondarily infected with Mycobacterium tuberculosis

Abstract

Mediastinal cysts are mostly congenital, but rarely, infections and malignancies can cause cystic degeneration of enlarged mediastinal lymph nodes. Diagnosis is challenging as the presenting symptoms are nonspecific. Surgical resection is the reference modality both for diagnosis and management. Secondary infection of mediastinal bronchogenic cyst with Mycobacterium tuberculosis is rare. Herein, we describe a young male who was managed as bronchial asthma with inhalational bronchodilators and glucocorticoids. Computed tomography revealed a cystic lesion in the subcarinal region. Endobronchial ultrasound-guided transbronchial needle aspiration was done to perform diagnostic and therapeutic aspiration of the cyst that showed infection with M. tuberculosis. A subsequent surgical resection confirmed the cystic lesion to be a bronchogenic cyst.

Pneumonia, pleurisy, mediastinitis, and mediastinal cyst infection secondary to endobronchial ultrasound-guided transbronchial needle aspiration

“…However, some patients present with symptoms due to compression of adjacent organs, cyst infection, etc. [ 21 ] The common symptoms are chest pain, dyspnea, hemoptysis or cough and expectoration due to recurrent cyst infections. [ 26 ] Chest CT or magnetic resonance imaging (MRI) examinations are clinically important for the diagnosis of mediastinal cysts.…”

“…[ 11 ] The use of EBUS-TBNA has related complications such as secondary infection and hemorrhage, especially for cystic lesions, which seems to have a greater potential to develop cystic infection, lung abscess, pleural infection or mediastinal infection than solid lesions of the mediastinum. [ 4 , 6 , 9 , 13 , 16 , 25 ] The reported infectious pathogens include Streptococcus, [ 5 – 6 , 16 – 17 , 24 – 25 , 30 – 31 ] Coryneform bacteria and Prevotella melaninogenica, [ 5 ] Staphylococcus, [ 4 , 24 ] Mycobacterium tuberculosis, [ 21 ] Haemophilus Influenza, [ 32 ] Eikenella corrodens, [ 24 , 33 ] Klebsiella pneumonia, Actinomyces odontolyticus, Gemella morbillorum, Prevotella buccae, Actinomyces, [ 30 ] among which the most of the reported bacteria are oral flora. During the procedure of EBUS-BNA, the bronchoscope and needle may be contaminated when passing through the oropharynx, thus carrying bacteria of the oral flora into the cyst.…”

“…About two-thirds of patients with mediastinal cyst remain asymptomatic. However, some patients present with symptoms due to compression of adjacent organs, cyst infection, etc [21] . The common symptoms are chest pain, dyspnea, hemoptysis or cough and expectoration due to recurrent cyst infections [26] .…”

“…[ 13 , 16 ] The most common complications are fever, infection (mediastinitis, pneumonia, mediastinal cyst infection, etc. ), hemorrhage, and pneumothorax, [ 12 – 14 , 16 – 17 ] unusual or rare complications include bronchoscope damage, [ 12 ] needle breakage, [ 18 ] pneumoperitoneum, [ 19 ] haemotympanum, [ 20 ] airway obstruction, [ 21 ] subcutaneous emphysema, [ 22 ] hemothorax, [ 23 ] and pericardial abscess. [ 24 ] The application of EBUS-TBNA in mediastinal cystic lesions is usually accompanied with a high incidence of infection.…”