Proceedings of the 2024 Classic Examples in Toxicologic Pathology XXXI

The 31st edition of the slide seminar “Classic Examples in Toxicologic Pathology” was held at the Department of Pathology at the University of Veterinary Medicine in Hannover, Germany, in March 2024. The meeting series is jointly organized with the ESTP (European Society of Toxicologic Pathology) and aims at presenting and discussing classical and novel cases of toxicologic and experimental pathology. This article reflects on 6 out of 10 presentations given at the seminar and includes images of representative lesions. They comprise cases of toxicologic pathology, induced directly or indirectly by a test item. We herein summarize findings with a progesterone receptor antagonist and its impact on uterine tumor development in rats; an example of hybridization-dependent off-target hepatotoxicity in rats administered a small interfering RNA (siRNA) conjugated to N-acetylgalactosamine (GalNAc) and the case of an orexin-1/-2 receptor antagonist with liver enzyme induction. We further include a case on reactive metabolites with associated liver findings, a study on findings induced by a GPR40 agonist and a presentation on dysgeusia and its translatability.