Adequately defining tumor cell proportion in tissue samples for molecular testing improves interobserver reproducibility of its assessment.

Gene mutation status assessment of tumors has become standard practice in diagnostic pathology. This is done using samples comprising tumor cells but also non-tumor cells, which may dramatically dilute the proportion of tumor DNA and induce false negative results. Increasing sensitivity of molecular tests presently allows detection of a targeted mutation in a sample with a small percentage of tumor cells, but assessment of tumor cellularity remains essential to adequately interpret the results of molecular tests.

Guidelines for May-Grünwald-Giemsa staining in haematology and non-gynaecological cytopathology: recommendations of the French Society of Clinical Cytology (SFCC) and of the French Association for Quality Assurance in Anatomic and Cytologic Pathology (AFAQAP).

Objective: Since the guidelines of the International Committee for Standardisation in Haematology (ICSH) in 1984 and those of the European Committee for External Quality Assessment Programmes in Laboratory Medicine (EQALM) in 2004, no leading organisation has published technical recommendations for the preparation of air-dried cytological specimens using May-Grünwald-Giemsa (MGG) staining.

Data Sources: Literature data were retrieved using reference books, baseline-published studies, articles extracted from PubMed/Medline and Google Scholar, and online-available industry datasheets.

Rationale: The present review addresses all pre-analytical issues concerning the use of Romanowsky's stains (including MGG) in haematology and non-gynaecological cytopathology.

Three Rounds of External Quality Assessment in France to Evaluate the Performance of 28 Platforms for Multiparametric Molecular Testing in Metastatic Colorectal and Non-Small Cell Lung Cancer.

Personalized medicine has gained increasing importance in clinical oncology, and several clinically important biomarkers are implemented in routine practice. In an effort to guarantee high quality of molecular testing in France, three subsequent external quality assessment rounds were organized at the initiative of the National Cancer Institute between 2012 and 2014. The schemes included clinically relevant biomarkers for metastatic colorectal (KRAS, NRAS, BRAF, PIK3CA, microsatellite instability) and non-small cell lung cancer (EGFR, KRAS, BRAF, PIK3CA, ERBB2), and they represent the first multigene/multicancer studies throughout Europe.