Severe Back Pain, Epigastric Distress and Refractory Nausea: An Unusual Presentation of Mediastinal Bronchogenic Cyst

Abstract

Bronchogenic cysts are congenital malformations from abnormal budding of embryonic foregut and tracheobronchial tree. We present a case of bronchogenic cyst with severe back pain, epigastric distress and refractory nausea and vomiting. A 44-year-old Hispanic female presented with a 3-week history of recurrent sharp interscapular pain radiating to epigastrium with refractory nausea and vomiting. She underwent cholecystectomy 2-years ago. Computed tomography (CT) abdomen at that time showed a subcarinal mass measuring 5.4 X 5.0 cm. Subsequent endoscopic ultrasound (EUS) diagnosed it as a bronchogenic cyst. Endobronchial ultrasound (EBUS) guided aspiration resulted in incomplete drainage and she was discharged after partial improvement. Current physical examination showed a heart rate of 126/min and respiratory rate of 20/min. Labs showed white cell count of 10.58X103/uL, elevated inflammatory markers, and hypokalemic metabolic alkalosis. Electrocardiogram showed non-specific T wave changes. CT chest showed increased size of the bronchogenic cyst (9.64 X 7.7 cm) with small right pleural effusion. This was consistent with partial cyst rupture or infected cyst. X-ray esophagram ruled out esophageal compression or contrast extravasation. Patient's symptoms were refractory to conservative management. The patient ultimately underwent right thoracotomy with cyst excision that resulted in complete resolution of symptoms. Cyst pathology was consistent with severe inflammatory changes. Bronchogenic cysts are the most common primary cysts of mediastinum with prevalence of 6%. The most common symptoms are chest pain, dyspnea, cough, and stridor. Our patient presented with back pain, epigastric distress, refractory nausea and vomiting. Back pain is caused by stretching of nerves supplying parietal pleura; while nausea is caused by stimulation of vagus nerve. Diagnosis is made by Chest X-Ray and CT chest. Magnetic resonance imaging (MRI) chest and EBUS are more sensitive and specific. Symptomatic cysts should be resected unless surgical risks are high. Asymptomatic cysts in younger patients should be removed due to low surgical risk and potential late complications (infection, hemorrhage or neoplasia). Watchful waiting has been recommended for asymptomatic adults or high-risk patients. Bronchogenic cyst can cause severe back pain and refractory nausea and vomiting. Prompt surgical excision can lead to complete symptom resolution and avoidance of future complications.Figure: Chest Xray showing right posterior mediastinal cyst (April 2017).Figure: CT Chest with contrast showing right posterior mediastinal cyst measuring 5.4 X 5.0 cm (May 2015).Figure: CT Chest with contrast showing right posterior mediastinal cyst measuring 9.64 X 7.7 cm (April 2017).