Histopathology is the study of microscopic changes or abnormalities in tissues. This data domain contains descriptions of tissue abnormalities (diagnosis), site of abnormality (location), and severity of lesions. Examples of endpoints: diagnosis, distribution, and severity of lesions, and indication of whether the observed lesion is neoplastic, metastatic, systemic, or malignant.
This data domain is part of Chemical Effects in Biological Systems (CEBS) database maintained by the National Toxicology Program.
At the link provided is a PDF and one or more folders containing data. The PDF describes the data, file types, and folder structure present.