[The 2015 classification of lung adenocarcinomas: Reproducibility in a Tunisian department specialised in thoracic pathology].

INTRODUCTION: The new classification of lung cancer contains modifications of terminology and a new subdivision of the tumors with the most relevant modifications concerning the group of adenocarcinomas. The latter has been increasing and represents nowadays the most frequent type. Our aim was to assess the reproducibility of the new classification through the experience of a Department of Pathology specialized in thoracic pathology.

METHODS: Our study included initially 106 cases diagnosed as adenocarcinomas and reviewed by 2 pathologists and 1 referee. Five cases were ruled out because they corresponded to squamous carcinoma according to the immunohistochemical findings. The same number of slides was reviewed without a limit of time. Statistical analysis was performed using the SPSS software. The Kappa index was estimated and a second coefficient: rho was analyzed.

RESULTS: A total concordance was noticed in 82 cases (81.2%) and a discordance was noticed in 19 cases (18.8%). The agreement degree was good with an index Kappa estimated to 0.743 and a rho index reaching 0.763.

CONCLUSION: Our study highlights the good reproducibility of the 2015 WHO classification of lung cancer among a trained team. Whereas, in order to improve the reproducibility of such a classification, even in non specialised departments, a training of the pathologists is necessary in order to highlight the prognostic impact of this classification.