International Harmonization of Rat Nomenclature

Ordering of words in diagnostic terms / synonyms
There are often several possibilities how to order the words of diagnostic terms, depending on personal preferences, sorting requirements or system capabilities. The majority of the Reconciliation Subcommittee is of the opinion that the ordering of words should not be a striking criterion to accept or reject a diagnosis, as far as the complete diagnostic term expresses a clear designation of the lesion.

In the Recommendation column of the nomenclature tables, words are arranged by placing the main diagnostic term first (e.g. tumor, adenoma, carcinoma, hyperplasia). In many cases, this is followed by words describing more details of the lesion, like the cell type (e.g. C-cell, follicular cell, squamous cell), growth pattern (e.g. cystic/papillary, glandular), sub-topography (e.g. intramural, uveal), etc., referred to in the text as "lesion descriptor". If the biological behavior is not clearly expressed by the lesion name itself, either "benign" or "malignant" is added for tumors at the end of the term (e.g. "tumor, basal cell, benign", "schwannoma, malignant"). This arrangement allows an easy grouping (sorting) of lesions with the result that lesions of the same kind are placed together (e.g. all hyperplasias, adenomas, carcinomas, etc.).

However, sometimes it might be useful to group lesions by cell type, e.g. to have all C-cell lesions (hyperplasia, adenoma and carcinoma) listed together. Since the meaning of the diagnostic term is not changed by a different ordering of words, such synonyms could be used as an alternative.

A summary of all diagnostic terms used in the Recommendation column of the nomenclature tables has been compiled and the two above mentioned alternatives are presented for comparison: For several lesions, additional (and different) arrangements of words are possible (not shown in the tables). Example:
  • histiocytoma, fibrous, benign
  • fibrous histiocytoma, benign
  • benign fibrous histiocytoma
Also such synonyms can be used.

Last Update: 21-Jun-2000