Alveolar capillary dysplasia with misalignment of pulmonary veins (ACD/MPV) is a rare neonatal lung disease with fatal outcome. Typically, respiratory symptoms present in the first 24 hours of life and patients die within the neonatal period. Atypical, delayed clinical presentations and/or longer survival have also been reported. Here, we studied the clinicopathologic relationship of ACD/MPV by examining 16 cases of ACD/MPV, focusing on atypical features. Based on the presence of diffuse vs. focal/patchy ACD/MPV histopathologic changes, we divided the cases into classic and nonclassic pathology groups. MPV was found in all ACD/MPV. Ten of 16 cases exhibited classic diffuse abnormalities, while 6 of 16 had a nonclassic focal/patchy distribution. However, among 7 patients with atypical clinical features, only 2 had nonclassic pathology, while 4 out of 9 clinically typical cases had nonclassic ACD/MPV pathology. Marked intrapulmonary aberrant arteriovenous vessels were present in all atypical cases. In conclusion, clinical presentation is not always correlated with histopathology in ACD/MPV. Atypical ACD/MPV should be suspected in any infants with fulminant pulmonary hypertension. Abnormal pulmonary veins and aberrant intraseptal vessels are the most important clues for diagnosis. Additional studies are needed for further elucidation of diagnostic histological criteria of atypical ACD/MPV and to explore its pathogenesis.

肺静脉未对准（ACD / MPV）的肺泡毛细血管发育不良是一种罕见的新生儿肺部疾病，具有致命的后果。通常，在生命的最初24小时内出现呼吸道症状，患者会在新生儿期内死亡。也有非典型的，延迟的临床表现和/或更长的生存期。在这里，我们通过检查16例ACD / MPV（非典型特征）来研究ACD / MPV的临床病理关系。根据弥漫性与局灶性/斑块状ACD / MPV组织病理学变化的存在，我们将病例分为经典和非经典病理学组。在所有ACD / MPV中都发现了MPV。16例中有10例表现出典型的弥漫性异常，而16例中有6例具有非典型的局灶性/斑块分布。但是，在7例具有非典型临床特征的患者中，只有2例具有非经典病理，9个临床典型病例中有4个患有非经典ACD / MPV病理。在所有非典型病例中均存在明显的肺内异常动静脉血管。总之，ACD / MPV的临床表现并不总是与组织病理学相关。任何患有暴发性肺动脉高压的婴儿均应怀疑为非典型的ACD / MPV。肺静脉异常和隔中血管异常是诊断的最重要线索。需要进一步的研究来进一步阐明非典型ACD / MPV的诊断组织学标准，并探讨其发病机理。任何患有暴发性肺动脉高压的婴儿均应怀疑是非典型的ACD / MPV。异常的肺静脉和隔中血管异常是诊断的最重要线索。需要进一步的研究来进一步阐明非典型ACD / MPV的诊断组织学标准，并探讨其发病机理。任何患有暴发性肺动脉高压的婴儿均应怀疑是非典型的ACD / MPV。异常的肺静脉和隔中血管异常是诊断的最重要线索。需要进一步的研究来进一步阐明非典型ACD / MPV的诊断组织学标准，并探讨其发病机理。