A 2-week-old infant, born after a 33 4/7-week gestation, presented with respiratory distress. Antenatal ultrasound had shown no abnormalities. The first week of life was complicated by a grade 1 respiratory distress syndrome for which she was treated with nasal continuous positive airway pressure and supplemental oxygen during 1 day. At the age of 2 weeks, she again developed signs of acute respiratory distress. Chest radiography showed a hyperexpanded left lung with bullous structures. Computed tomography (CT)-scan (Figure 1) showed a cystic lesion that was primarily misdiagnosed as congenital cystic adenomatoid malformation. Respiratory symptoms and supplemental oxygen requirement gradually decreased within 1 week. She remained asymptomatic and a spontaneous resolution was confirmed 6 months later (Figure 2).
CT scan at the age of 2 weeks showing hyperinflation of the left upper lobe with multiple bullous structures, and a for PPIE characteristic line-and-dot pattern (arrows).
As we were impressed by the spontaneous resolution of these large cystic lesions, the first CT imaging was reinterpreted subsequently. This reinterpretation showed a typical line-and-dot pattern within the air-filled cysts, characteristic for persistent pulmonary interstitial emphysema (PPIE). PPIE is a rare condition typically associated with mechanical ventilation of preterm infants, but also seen in term and non-ventilated infants.[1,2] The differential diagnosis of PPIE is broad, including congenital cystic lung lesions, such as congenital cystic adenomatoid malformation, lobar emphysema and bronchogenic cysts. CT scan is the diagnostic tool of choice to diagnose PPIE, with a characteristic line-and-dot pattern, attributed to gas in the pulmonary interstitial space surrounding bronchovascular bundles that appear as linear or punctuate soft-tissue densities within the cystic radiolucencies. The management of PPIE is either surgical or conservative, depending on the severity of respiratory symptoms. Spontaneous resolution of both localized and diffuse PPIE has been reported. This case demonstrates that even large localized PPIE lesions can resolve spontaneously, and that a conservative approach may be appropriate when these lesions are not accompanied by respiratory symptoms.
J Perinatol. 2012;32(3):241-242. © 2012 Nature Publishing Group