The INHAND (International Harmonization of Nomenclature and Diagnostic Criteria for
Lesions in Rats and Mice) Project (www.toxpath.org/inhand.asp) is a joint initiative of
the Societies of Toxicological Pathology from Europe (ESTP), Great Britain (BSTP), Japan
(JSTP) and North America (STP) to develop an internationally accepted nomenclature for
proliferative and nonproliferative lesions in laboratory animals. The purpose of this
publication is to provide a standardized nomenclature for classifying microscopic lesions
observed in the female reproductive tract of laboratory rats and mice, with color
photomicrographs illustrating examples of some lesions. The standardized nomenclature
presented in this document is also available electronically on the internet
(http://www.goreni.org/). Sources of material included histopathology databases from
government, academia, and industrial laboratories throughout the world. Content includes
spontaneous and aging lesions as well as lesions induced by exposure to test materials.
There is also a section on normal cyclical changes observed in the ovary, uterus, cervix
and vagina to compare normal physiological changes with pathological lesions. A widely
accepted and utilized international harmonization of nomenclature for female reproductive
tract lesions in laboratory animals will decrease confusion among regulatory and
scientific research organizations in different countries and provide a common language to
increase and enrich international exchanges of information among toxicologists and
pathologists.