To the Editor
We read with great interest the conference proceedings of the Amsterdam placental workshop group (Khong et al1) in the July 2016 issue of the Archives of Pathology & Laboratory Medicine, titled “Sampling and definitions of placental lesions.” It led us to some considerations concerning the pathologist's role in the clinical management of pregnancies.
We fully agree with the authors that the guidelines need to cover reporting placentas in tertiary centers as well as in community hospital and district general hospitals, but also need to be relevant to the scientific research community.
As surgical pathologists, we are used to classifying, staging, grading, counting, and measuring: pathologists are taxonomy addicted, and when approaching placental pathology some fixed certainties of life seem to weaken. Actually, a great effort has been made during the last few years to apply surgical pathology diagnostic criteria to placental pathology.2,3
Since the publication of the Amsterdam consensus statement, we have applied the proposed guidelines to our daily work routine. Nonetheless, we would like to express some concerns about the clinical usefulness of such a reporting scheme.
The proposed diagnostic scheme is easily applicable to routine diagnostics, but, quite surprisingly, we did not find any comment on chorangiosis and only a little advice about clinicopathologic correlation.
Chorangiosis/villous hypervascularity is a frequent feature of placentas (nearly 30% of cases), alone or together with other hypoxia-related lesions.4 Its significance is still not completely clear, but it is traditionally related to intrauterine hypoxia/underperfusion, diabetes, and many other conditions. As Stanek4 recently stated, chorangiosis/villous hypervascularity per se is not related to poor pregnancy outcome, but it can be considered as the epiphenomenon of intrauterine placental hypoxia. On some occasions, chorangiosis/hypervascularity is the very first readily observed lesion, and it may arouse suspicions about possible hypoxia, leading us to look for other, sometimes very subtle lesions. We actually describe chorangiosis/villous hypervascularity in the “other findings” sections of the histology report. Because of its frequency, we believe that it should be documented in the diagnostic report, at least to “facilitate further clinicopathologic study.”1
Clinicopathologic correlations are mentioned only regarding distal villous hypoplasia and accelerated villous maturation, related to early-onset fetal growth restriction and placental insufficiency, respectively. On the contrary, delayed villous maturation, traditionally related to diabetes5 and often associated with chorangiosis/hypervascularity, is simply described and graded, without any mention of its possible etiology/pathogenesis.
We believe that this consensus statement is a milestone in placental pathology: standardization of nomenclature and clearness of terminology is very important in routine diagnostics. We are aware that the need for a widely accepted sampling protocol and diagnostic terminology was the first and principal aim of the consensus statement. Otherwise, clinicopathologic correlations are a pressing topic in daily practice, but they are still driven case by case and only when clinical history is strongly consistent with placental morphology.