Department of Pathology, Children's Hospital of Philadelphia, 3401 Civic Center Blvd, Philadelphia, PA, USA; Department of Pathology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA.
Department of Pathology, Massachusetts General Hospital, 55 Fruit St, Boston, MA, USA; Department of Pathology, Harvard Medical School, Boston, MA, USA.
Placenta. 2021 Jan 15;104:295-302. doi: 10.1016/j.placenta.2020.12.011. Epub 2020 Dec 22.
Inverted discordant p57 expression in chorionic villi, characterized by a loss of nuclear staining in cytotrophoblast with retained staining in villous stromal cells, is rarely described. Following an incidental finding of such peculiar staining pattern in rare clusters of dysmorphic chorionic villi (DCV) in a perinatal autopsy case, we reviewed our archived cases of third trimester placentas with DCV to systematically analyze these curious foci.
Histopathological features and p57 expression of 26 placentas with DCV were carefully studied by light microscopy and p57 immunohistochemistry. p57 pattern of expression was correlated with a comprehensive list of maternal, fetal, and placental features to reveal potential associations.
Inverted discordant p57 expression was observed in 17/26 (65.4%) cases, encompassing all cases with aberrant p57 immunostaining in this series. Among the many features investigated, only the focality (occurring as a single focus) of DCV (Fisher's exact test, p = 0.008) and small cluster size of ≤30 villi (Fisher's exact test, p = 0.034) correlated significantly with inverted discordant p57 staining. Other common features of DCV with inverted discordant p57 expression include larger villous size compared with surrounding tertiary villi (13/17, 76.4%), prominent but not hyperplastic and focally to moderately hyperplastic syncytiotrophoblast (17/21, 80.9%), abnormal shapes/irregular contours (17/22, 77.3%), and markedly hypovascular villous stroma (11/17, 64.7%). No distinctive maternal or fetal features were observed.
Inverted discordant p57 expression in DCV of third trimester placentas is likely underreported, and might not be an unusual occurrence outside of suspected molar specimens.
在绒毛中观察到反向不协调的 p57 表达，其特征是滋养细胞的核染色缺失，而绒毛间质细胞的染色保留，这种情况很少见。在一例围产期尸检中罕见的畸形绒毛（DCV）的少数簇中偶然发现这种特殊的染色模式后，我们回顾了我们存档的有 DCV 的晚期胎盘病例，以系统地分析这些奇特的病灶。
通过光镜和 p57 免疫组化仔细研究了 26 例 DCV 胎盘的组织病理学特征和 p57 表达。p57 表达模式与一系列全面的母体、胎儿和胎盘特征相关联，以揭示潜在的关联。
在 26 例病例中有 17 例（65.4%）观察到反向不协调的 p57 表达，包括该系列中所有异常 p57 免疫染色的病例。在研究的众多特征中，只有 DCV 的局灶性（单个病灶）（Fisher 精确检验，p=0.008）和≤30 个绒毛的小簇大小（Fisher 精确检验，p=0.034）与反向不协调的 p57 染色显著相关。具有反向不协调 p57 表达的 DCV 的其他常见特征包括与周围三级绒毛相比更大的绒毛大小（13/17，76.4%）、突出但非增生性和局灶性至中度增生性合体滋养层（17/21，80.9%）、异常形状/不规则轮廓（17/22，77.3%）和明显血管减少的绒毛间质（11/17，64.7%）。未观察到明显的母体或胎儿特征。
在晚期胎盘的 DCV 中，反向不协调的 p57 表达可能被低估了，并且在疑似葡萄胎标本之外，可能不是不常见的情况。
