The Impact of the Fourth Edition of the WHO Classification of Lung Tumours on Histological Classification of Resected Pulmonary NSCCs
2016 (English)In: Journal of Thoracic Oncology, ISSN 1556-0864, E-ISSN 1556-1380, Vol. 11, no 6, 862-872 p.Article in journal (Refereed) Published
INTRODUCTION: Histopathological classification of lung cancer is of central importance in the diagnostic routine and guides therapy in the majority of patients. The 4(th) edition of the WHO classification was recently published and includes changes to the diagnostic procedure of non-small cell carcinomas (NSCC) with more emphasis on immunohistochemical (IHC) staining.
METHODS: 656 unselective cases of resected pulmonary NSCC were diagnosed according to the 2004 WHO classification. After IHC staining with cytokeratin 5, p40, p63, thyroid transcription factor 1 (clones 8G7G3/1 and SPT24) and napsin A the diagnoses were revised in accordance with the new 4(th) edition of the WHO classification.
RESULTS: Reclassification led to a new histological annotation in 36 (5%) of the 656 cases. Most notable was the decrease of cases previously classified as large cell carcinomas (56 vs. 12 cases). This was partially due to the exclusion of 21 neuroendocrine tumors from this group, while 20 cases were ascribed to the group of adenocarcinoma based on IHC markers. Only 7 cases of adenocarcinoma or squamous cell carcinoma were reclassified after the addition of IHC staining. There was a substantial overlap in staining properties between different markers of squamous and adenocarcinomatous differentiation, respectively, but in 17-31 cases (3-5%) the diagnosis depended on the choice of markers.
CONCLUSIONS: The 4(th) edition of the WHO classification of lung tumours leads to changes of histological type in 5% of resected NSCC cases. The incorporation of IHC staining in NSCC diagnostics demands awareness that the choice of ancillary stains has an effect on diagnosis.
Place, publisher, year, edition, pages
2016. Vol. 11, no 6, 862-872 p.
Clinical Laboratory Medicine
Research subject Pathology
IdentifiersURN: urn:nbn:se:uu:diva-278886DOI: 10.1016/j.jtho.2016.01.020ISI: 000377641700010PubMedID: 26872818OAI: oai:DiVA.org:uu-278886DiVA: diva2:907114
FunderSwedish Cancer Society