A Rare Case of Mediastinal Bronchogenic Cyst Infected by Salmonella enteritidis

Abstract

Bronchogenic cysts are rare congenital malformations which arise from abnormal budding of the primitive tracheobronchial tube and can localize to either the mediastinum or lung parenchyma. They remain clinically silent in most adults unless they become infected or are large enough to compress adjacent structures. Infections involving bronchogenic cysts are often polymicrobial. Gram-positive, Gram-negative, and mycobacterial infections have been reported, though frequently a pathogen is not identified. We present the case of a 46-year-old female with known history of bronchogenic cyst who presented with suspected postobstructive pneumonia. She underwent cyst excision with culture positive for Salmonella enteritidis, an extremely rare finding on review of the literature. The patient recovered following a three-week course of antibiotics for extraintestinal salmonellosis.

Management of infected recurrent mediastinal bronchogenic cyst with tuberculous mediastinal lymphadenitis

“…Cysts located in the lung are more prone to infection, as against their mediastinal counterparts owing to their exposition/communication to the tracheobronchial tree [1].…”

“…The unique and rareness of this presentation go by the mediastinal bronchogenic cyst in our patient, with no communication to the adjacent structures, yet turning infections possibly through a hematogenous route. Organisms such as pneumococcus, peptococcus, E. coli, H. influenzae, Mycobacterium kansasii, and avium complex have been reported to cause infections in the domain of bronchogenic cysts [1].…”

“…Abnormal budding of the tracheobronchial tree is known to be the initiating cause of cystic formation, whose location is principally determined by the stage of budding. The cyst is likely to present in the mediastinum in early stages of malformation, which is most commonly observed, otherwise in the lung parenchyma at later stages [1].…”