International Harmonization of Rat Nomenclature

NACAD nomenclature
The nomenclature was established in 1996 by industry pathologists from the NACAD group, a representative from STP, and staff members of Fraunhofer ITA. The goal of this initiative was to amalgamate the STP and the RITA systems and to create a nomenclature which can be easily used in electronic data processing systems.
  • The biological behavior of each lesion is clearly defined in the name of the lesion and in addition by a flag in the NACAD data base lexicon. In the nomenclature tables, this is indicated by printing one of the following abbreviations in parenthesis at the end of each lesion name:

      N = non-preneoplastic proliferative lesion
      H = hyperplastic lesion
      B = benign tumor
      M = malignant tumor
      S = malignant systemic tumor

  • Language: US English is used.

  • Modifiers are used to subdivide lesions into different cell types or growth patterns. They are printed in italics and placed after the lesion name in brackets (multiple modifiers are separated by semicolons). The use of most of the modifiers is facultative.
See also
Recommended RAT nomenclature
WHO/IARC/RITA nomenclature
STP nomenclature

Last Update: 21-Jun-2000