[Pathological diagnosis, work-up and reporting of breast cancer. Recommendations from the 4th Breast Cancer Consensus Conference].

There have been some relevant changes in the diagnosis and treatment of breast cancer to implement the updating of the 2016 recommendations made during the 3rd national consensus conference on the disease. Following a wide interdisciplinary consultation, the present recommendations have been finalized after their public discussion at the 4th Hungarian Breast Cancer Consensus Conference. The recommendations cover non-operative, intraoperative and postoperative diagnostics, the determination of prognostic and predictive markers and the content of the cytology and histology reports. Furthermore, it touches some special issues such as the current status of multigene molecular markers, the role of pathologists in clinical trials and prerequisites for their involvement, some relevant points about the future. The most important changes include the integration of the TNM 8th edition, the WHO classification of breast tumors 5th edition, the ASCO/CAP HER2 assessment guidelines from 2018, and the Yokohama terminology for cytology reporting; a more detailed text on tumor-infiltrating lymphocytes and size determination after neoadjuvant therapy and a broader discussion of molecular tests.