정답은 brochial cyst 입니다.

 

CT상에서 비교적 margin이 분명한 low attenuated mass의 형태를 보이고 있습니다.

 

다음은 brochial cyst 의 개략적인 내용입니다.

 

Bronchogenic cysts arise from anomalous budding of the foregut during development and represent part of the spectrum of bronchopulmonary foregut malformations . They can occur at any point throughout the tracheobronchial tree. Cervical, intrapleural, cutaneous, esophageal, cardiac, and subdiaphragmatic retroperitoneal bronchogenic cysts are unusual occurrences but have been reported . These lesions, although rare, are among the most common lower respiratory tract malformations

 

Clinical features — Affected patients typically present during the second decade of life with recurrent coughing, wheezing (which may simulate asthma), and pneumonia, but they may become symptomatic in infancy or adulthood . Newborns with rapidly enlarging central cysts can develop respiratory distress, cyanosis, and feeding difficulty . Bronchogenic cysts also may be detected as incidental findings on chest radiographs.

Diagnosis — Bronchogenic cysts appear on chest radiograph as round water-density masses that may have air-fluid levels associated with previous or current infection . CT typically shows sharply marginated cystic mediastinal masses of soft tissue or water attenuation . Lesions that appear solid on CT usually can be characterized as cystic by MRI. The radiographic appearance of bronchogenic cysts and other developmental anomalies of the lung is discussed in detail separately.

 

Management — The management of a bronchogenic cyst consists of surgical excision by partial or total lobectomy. This procedure is curative. Controversy exists regarding the need for resection when patients are asymptomatic. recommend surgery in all cases because of the likelihood of eventual development of symptoms and the potential for serious illness . In addition, malignant degeneration may occur with this disorder, as in other congenital cystic anomalies . Although surgical excision is typically straightforward, operative complications have been reported . The prenatal ultrasound identification of large cysts compressing cardiovascular structures warrants in utero thoracentesis to prevent fetal hydrops