Fukunaga Masaharu, Katabuchi Hidetaka, Nagasaka Tetsuro, Mikami Yoshiki, Minamiguchi Sachiko, Lage Janice M
Department of Pathology, Jikei University, Tokyo, Japan.
Am J Surg Pathol. 2005 Jul;29(7):942-7. doi: 10.1097/01.pas.0000157996.23059.c1.
Surgical pathologists often encounter hydropic villi in products of conception at the first trimester and must determine whether the villi represent complete hydatidiform mole (CM), partial hydatidiform mole (PM), or hydropic abortion (HA). The distinction between these is important for determining the appropriate treatment of patients. This study assessed interobserver and intraobserver variability in the histologic diagnosis of hydatidiform mole among 5 placental pathologists. To evaluate interobserver variability, one representative slide from each of 50 mixed cases of PM, CM, and HA of the first trimester were circulated among 5 placental pathologists. All pathologists used the same histologic criteria by Szulman and Surti. For the second round, the same cases were submitted with DNA ploidy data. For the third round, the slides were recoded and distributed to assess intraobserver agreement. Kappa (kappa) value was calculated for the interobserver agreement in the first and second rounds. There was agreement among 4 or 5 pathologists for only 30 of 50 cases in the first round. There were problems in differentiating between PM and HA in most of the remaining 20 cases. The kappa values varied from poor (kappa = -0.104) to excellent (kappa = 0.761) in the first round. In the second round, there was agreement in 39 of 50 cases and the level of agreement remarkably increased, ranging from fair to good (kappa = 0.552) to excellent (kappa = 0.851). The number of discrepant cases, PM versus HA, was reduced to 4. In 7 cases, there were difficulties in distinguishing CM from HA. The intraobserver agreement ranged from 50% to 90%. Poor interobserver agreement was demonstrated when histology alone was used for diagnosis. Discordance was most frequently seen in PM versus HA and resulted from difficulty in evaluating trophoblastic hyperplasia. Polar trophoblastic growth seen in HA could also be observed in PM. The addition of ploidy data resulted in a significant improvement in concordance. Ploidy study is useful in equivocal cases. Significant interobserver and intraobserver variability was observed even among placental pathologists. New histologic criteria adaptable to differentiation of early lesions are needed.
手术病理学家在孕早期的妊娠产物中经常会遇到水肿绒毛，必须确定这些绒毛代表的是完全性葡萄胎（CM）、部分性葡萄胎（PM）还是水肿性流产（HA）。区分这些情况对于确定患者的适当治疗方法很重要。本研究评估了5名胎盘病理学家在葡萄胎组织学诊断中的观察者间和观察者内变异性。为了评估观察者间变异性，从50例孕早期PM、CM和HA的混合病例中各选取一张代表性切片，分发给5名胎盘病理学家。所有病理学家都采用了Szulman和Surti相同的组织学标准。第二轮，提交相同病例并附上DNA倍体数据。第三轮，对切片重新编码并分发以评估观察者内一致性。计算第一轮和第二轮观察者间一致性的Kappa（κ）值。第一轮中，50例病例中只有30例有4名或5名病理学家达成一致意见。其余20例中的大多数在区分PM和HA方面存在问题。第一轮的κ值从差（κ = -0.104）到优（κ = 0.761）不等。第二轮中，50例病例中有39例达成一致意见，一致性水平显著提高，从一般（κ = 0.552）到良好（κ = 0.851）再到优（κ = 0.851）。PM与HA之间的不一致病例数减少到4例。有7例病例在区分CM和HA方面存在困难。观察者内一致性范围为50%至90%。仅使用组织学进行诊断时，观察者间一致性较差。不一致最常出现在PM与HA之间，原因是难以评估滋养层细胞增生。HA中可见的极向滋养层细胞生长在PM中也可能观察到。加入倍体数据后，一致性有显著改善。倍体研究在疑难病例中很有用。即使在胎盘病理学家中也观察到了显著的观察者间和观察者内变异性。需要适用于早期病变鉴别的新组织学标准。
