De Paepe Monique E, V Benny Merline Kocheekkaran, Priolo Lauren, Luks Francois I, Shapiro Svetlana
1 Department of Pathology, Women and Infants Hospital of Rhode Island, USA.
2 Department of Pathology and Laboratory Medicine, The Warren Alpert Medical School of Brown University, Rhode Island, USA.
Pediatr Dev Pathol. 2017 Sep-Oct;20(5):432-439. doi: 10.1177/1093526616686455. Epub 2017 Jan 26.
The cellular mechanisms underlying the microvascular dysangiogenesis of bronchopulmonary dysplasia (chronic lung disease of the newborn) remain largely undetermined. We report unusual pulmonary vascular findings in a 27-week-gestation male newborn who died on the second day of life from intractable respiratory failure, following a pregnancy complicated by prolonged membrane rupture and persistent severe oligohydramnios. As expected, postmortem examination revealed pulmonary hypoplasia (lung/body weight ratio: 2.23%; 10th percentile for 27 weeks: 2.59%). In addition, lung microscopy revealed complex networks of non-sprouting, tortuous, and bulbously dilated capillaries, randomly distributed in widened airspace septa. Anti-smooth muscle actin immunohistochemistry demonstrated immunoreactive central densities within capillary lumina, suggestive of intravascular pillar formation. The plexus-forming, non-sprouting type of angiogenesis and apparent transluminal pillar formation are consistent with intussusceptive ("longitudinal splitting") angiogenesis. In concordance with previous observations made in human fetal lung xenografts, these findings support the notion that human postcanalicular lungs have the capacity to switch from sprouting to non-sprouting, intussusceptive-like angiogenesis, possibly representing an adaptive response activated by hemodynamic flow alterations and/or hypoxia. The possible relationship between the intussusceptive-like vascular changes observed in this case and the microvascular dysangiogenesis characteristic of bronchopulmonary dysplasia remains to be determined.
支气管肺发育不良（新生儿慢性肺病）微血管发育异常的细胞机制在很大程度上仍未明确。我们报告了一名孕27周的男性新生儿的异常肺血管表现，该新生儿在出生后第二天因顽固性呼吸衰竭死亡，其母亲孕期存在胎膜早破时间延长和持续性严重羊水过少的情况。正如预期的那样，尸检显示肺发育不全（肺/体重比：2.23%；27周时第10百分位数为2.59%）。此外，肺组织显微镜检查发现，在增宽的气腔间隔中随机分布着复杂的非芽生、迂曲且呈球囊状扩张的毛细血管网络。抗平滑肌肌动蛋白免疫组织化学显示毛细血管腔内有免疫反应性中心密度，提示血管内柱形成。这种形成丛状、非芽生型的血管生成以及明显的腔内柱形成与套叠式（“纵向分裂”）血管生成一致。与先前在人胎肺异种移植中的观察结果一致，这些发现支持这样一种观点，即人类小支气管后肺具有从芽生血管生成转变为非芽生、类似套叠式血管生成的能力，这可能代表了一种由血流动力学改变和/或缺氧激活的适应性反应。该病例中观察到的类似套叠式血管变化与支气管肺发育不良的微血管发育异常之间的可能关系仍有待确定。
