Occult Cystic Hygroma Of The Mediastinum Presenting As Tension Pneumothorax In A Young Adult: A Case Report

摘要

We report a highly unusual presentation of occult mediastinal cystic hygroma. An eighteen year old patient presented to the emergency department with an acute onset of dyspnea and a physical examination notable for tracheal deviation. A chest radiograph and subsequent CT scan of the chest revealed tracheal and mediastinal deviation along with a massive right pleural effusion and near total collapse of the right lung. Following urgent tube decompression the patient underwent thoracotomy to excise three large cystic masses. Histopathologic analysis confirmed a diagnosis of cystic hygroma arising from the mediastinum. Introduction Cystic hygroma are rare benign tumors of presumed congenital origin. These tumors are composed of lymphoid tissue and lymph fluid within an endothelial lining containing multiple cysts ranging in diameter from a few millimeters to several centimeters. They are thought to occur as a result of ineffective communication between the lymphatic and venous systems. Most are diagnosed in infancy, 95% are found within the neck or axillae 1 . Some cystic hygroma remain undiagnosed until adulthood by dint of their anatomic location within the thoracic or abdominal cavities. The presentation of these lesions is quite different than that of lesions located at classic sites; thus, we propose the term occult cystic hygroma to describe these tumors. Small series of intrathoracic hygroma have been previously reported 2 3 . This particular case is unique in that the patient presented with signs and symptoms of tension pneumothorax (mediastinal shift, tracheal deviation, and acute onset respiratory distress) and the surgical exploration revealed cysts arising from three different mediastinal compartments. Case Report An eighteen year old male presented to the emergency department with rapidly progressive shortness of breath, chest tightness, and a physical exam significant for tracheal deviation. The patient had a past medical history significant only for tuberculosis diagnosed three years prior. A chest roentgenogram revealed a massive right side pleural effusion with significant tracheal and mediastinal shift (Fig. 1).