Aims We wanted to improve the quality of histopathology addenda and amendments by introducing standardised nomenclature and procedures.

Methods We standardised amendment and addenda definitions, implemented a pathologist visual work tool, and evaluated and quantitated all amendments and addenda for 3 months prior to implementation and 17 months after.

Results In the 3-month pre-intervention period, 32 of 979 addenda (3.3%) were misused and 18 of 98 amendments (18.4%) were incorrectly classified. In the 17-month post-intervention period, 57 of 5906 addenda (1.0%) were misused and 54 of 752 amendments (7.2%) were incorrectly classified. These differences were statistically significant (p<0.0001).

Conclusions The introduction of standardised nomenclature and a visual work tool significantly improved the quality of histopathology addenda and amendments.