Case Presentation: A ten month old male born at term with a past medical history of pneumonia diagnosed at six months of age presented with fever, cough and respiratory distress. His exam was notable for decreased breath sounds and crackles over the entire left lung. A chest x-ray was obtained and demonstrated near complete opacification of the left lung with concern for left lower lobe pneumonia and atelectasis. The patient’s labs were notable for a leukocytosis to 26,800 cells/µL with a bandemia of 33%, an elevated CRP to 20 mg/dL, and an elevated procalcitonin to 27.1 ng/mL. The patient received supplemental oxygen and intravenous ampicillin for a suspected pneumonia. Despite over twenty-four hours of intravenous antibiotics, the patient continued to require supplemental oxygen and had no improvement in his lung exam. A repeat chest x-ray demonstrated continued opacification of the entire left lung with concern for a leftward mediastinal shift (image 1). Additionally, the chest x-ray from the patient’s previous pneumonia diagnosis was also concerning for a leftward mediastinal shift. At this point, a chest computed tomography (CT) scan with contrast was obtained and demonstrated a cystic posterior mediastinal mass with complete compression of the left mainstem bronchus and anterior displacement of the trachea (image 2). Cardiothoracic surgery was consulted and the patient underwent right thoracotomy with mass resection on hospital day nine. Pathology review was consistent with an esophageal duplication cyst. He was discharged on post operative day three in stable condition. A repeat chest x-ray one month post-resection demonstrated complete resolution of the previously observed left lung opacification.
Discussion: An esophageal duplication cyst (EDC) is a rare congenital anomaly, estimated to occur in 1 in 8,200 births with a male predominance. While EDCs can occur in the cervical or abdominal portion of the esophagus, the thoracic segment of the esophagus is the most common location. The differential diagnosis of EDCs includes bronchogenic cysts, mature cystic teratomas, pericardial cysts, congenital cystic adenomatoid malformations, neurogenic tumors and abscesses. Over 80% of children with EDCs will present with symptoms before the age of two. The most common presentations include respiratory symptoms and dysphasia. In a case report of two children with EDCs, one presented at two and a half years of age with recurrent pneumonia, and the second presented at eleven months with recurrent pneumonia and dysphagia. Similarly, our patient presented with recurrent pneumonia due to the posterior mediastinal location of the EDC leading to compression of the left mainstem bronchus and an increased propensity for infections. EDCs are surgically resected to prevent mass effect, rupture, secondary infection, mediastinitis and malignant transformation.
Conclusions: Recurrent pneumonia is defined as two or more radiographically confirmed episodes of pneumonia in one year, or more than three radiographically confirmed episodes of pneumonia in a lifetime. The differential diagnosis includes anatomic lesions including EDCs, respiratory tract disorders, gastroesophageal reflux, aspiration, and immunologic disorders. In cases of recurrent pneumonia with evidence of unilateral volume loss and mediastinal shift on imaging, EDCs should be considered as a possible etiology.
