Figure 1

Lung tissue morphology. a: normal control (healthy lung tissue obtained from lobectomy in a 1-month old infant with congenital cystic adenoid malformation), optical microscopy, 20 ×; b-i: patient's lung tissue obtained by open-chest biopsy at 7 months. a: Normal lung tissue, HE, 20 ×; b: low-power microscopy shows interstitial thickening, alveolar type II cell hyperplasia and intra-alveolar amorphous material (HE 20 ×); c: sparse intracellular and intra-alveolar proteinaceous material accumulation (PAS, 20 ×); d: Diffuse interstitial fibrosis (MT, 20 ×); e: Small collagen fiber deposition in the interstitium (VGFE, 20 ×); Regular density and distribution of pulmonary capillary vessels (factor VIII, 20 ×); g: Higher magnification shows leukocyte intra-alveolar accumulation and interstitial infiltration (CD45, 40 ×); h: intra-alveolar cells mostly correspond to macrophages (CD68, 400 ×); i: alveolar epithelial lining consists of hyperplastic type-II cells (proSP-B, 40 ×).