Neuroendocrine cell hyperplasia of infancy (NCHI) is also a non lethal disease characterized by tachypnea without respiratory failure. The human airway epithelium contains highly specialized pulmonary neuroendocrine cells (PNEC) system. It's function remains unknown but is hypothysed to act in modulation of fetal lung growth and in post-natal stem cell condition [199] . The PNEC system permits synthesis and release of serotonin and neuropeptides such as bombesin [200] . As normal bombesin levels decrease after mid-gestation, its overexpression in NCHI could be attributed to a nonregression of neuroendocrine cells [201] . Clinical presentation is typically a respiratory distress in post-natal young infant (mean age 3.8 months in a large serie, but cases in older children have been reported [202] . HRCT shows patchy centrally ground-glass opacifications and air trapping [203] . On lung biopsy, the histological abnormality is hyperplasia of neuroendocrine cells within bronchioles documented by bombesin immunohistochemistry. The follow-up reveals in some cases the persistence of tachypnea and oxygen requirement for several months. Usually, there is a good prognosis [7, 8, 196, 202] .