Spontaneous Multiseptated Cystic Pneumomediastinum in a Term Newborn

Abstract

Pneumomediastinum usually occurs after assisted ventilation. Spontaneous pneumomediastinum without preceding assisted ventilation, and presenting as a huge cystic mass in a term newborn infant has rarely been reported. We report a term baby who developed respiratory distress at 2 days of age. A huge cystic tumor of the thymus or a congenital mediastinal cystic tumor was initially suggested by chest radiography and computed tomography. Follow-up chest film revealed a "spinnaker sail sign" which is a typical radiographic presentation of pneumomediastinum.

Decreased heart sound in a healthy newborn: Spontaneous multiseptated cystic pneumomediastinum with delayed respiratory distress

“…The chest CT findings of pneumomediastinum in neonates show a multiseptated lesion indicating the involvement of the fascia of the mediastinal structures that connect to the thymus 4,11) . The chest CT finding in our patient supports that neonatal pneumomediastinum tends to loculate and has a lobulated internal septum owing to the fact that the involved fascia of neonates is firm and strong and prevents further dissection of the mediastinal tissue, thereby preventing development of subcutaneous emphysema 5,10) .…”

“…It is postulated that pneumomediastinum may develop spontaneously due to forceful inspiratory effort and nonhomogeneity of ventilation, resulting in alveolar overdistention and rupture with eventual dissemination of air to the hilar space 5) . As air accumulates in the mediastinum, few symptoms are observed until increased mediastinal pressure causes cardiovascular or respiratory compromise by decreasing venous return to the heart or by compressing major bronchi 6) .…”

Multiseptated Cystic Pneumomediastinum in a Term Newborn: Cystic and Bubbly Lesion on Chest X-ray

“…4 Congenital mediastinal cystic mass includes congenital cyst, congenital cystic adenomatoid malformation (CCAM) and congenital lobar emphysema (CLE). 5 We report a term neonate with spon taneous multiseptated cystic pneumomediastinum suspected as congenital mediastinal cystic mass.…”

Spontaneous neonatal pneumomediastinum

“…Although most reported cases of neonatal pneumomediastinum ensue exposure to positive pressure in the setting of premature or diseased lungs [1][2][3], spontaneous pneumomediastinum that occurs in the absence of clearly defined precipitating factors, has rarely been reported [4,5]. Pathogenesis of pneumomediastinum was first demonstrated experimentally by Macklin in 1939 [6].…”

“…Air tends to loculate around the thymus and sometimes can even dissect within the interlobular and connective tissue septa of the thymic capsule, giving rise to a cystic appearance. It is postulated that this cystic appearance is uncommon in older children and adults because the thymus and its fascia undergo atrophy and are unable to contain a sudden air leak [5,8].…”