ABSTRACT
In the recently published 2015 World Health Organization (WHO) classification of tumors of the lungs, all neuroendocrine tumors of the lungs are presented for the first time in one single chapter. In this classification, high-grade small cell lung cancer (SCLC) and large cell neuroendocrine carcinoma (LCNEC) are differentiated from intermediate grade atypical carcinoids (AC) and low-grade typical carcinoids as well as from preinvasive lesion diffuse neuroendocrine hyperplasia DIPNECH. In the 2004 WHO classification, SCLC and carcinoids each had a separate chapter and LCNEC was listed in the chapter on large cell carcinoma of the lungs. The new WHO classification also gives some recommendations for the diagnosis on small biopsies. This review describes morphological, immunohistochemical, and genomic characteristic of these tumors according to the new classification.