Atypical Placental Site Nodule and Related Lesions: Interobserver Reproducibility.

ABSTRACT: Placental site nodule (PSN) and atypical placental site nodule (APSN) are chorionic-type intermediate trophoblastic lesions, the latter characterized by worrisome histologic characteristics and risk for subsequent trophoblastic neoplasia, mainly epithelioid trophoblastic tumor (ETT). There is no consensus or evidence-based criteria on which and how many features are needed for APSN diagnosis. We assessed interobserver reproducibility of APSN, PSN, and ETT. Five expert pathologists evaluated representative whole slide images (1 hematoxylin-and-eosin and 1 Ki-67/AE1-AE3 immunohistochemical stain) of 50 cases with APSN, PSN, or ETT index diagnosis and recorded independently diagnostic impressions and worrisome histologic characteristics (extensive lesional tissue, severe nuclear atypia, hyper

SUBMITTER: Lin LH 

PROVIDER: S-EPMC12777547 | biostudies-literature | 2026 Feb

REPOSITORIES: biostudies-literature