Neuroendocrine neoplasms of the lung: a pathology update

Abstract

Summary Purpose Neuroendocrine tumors and neuroendocrine carcinomas in the lung are distinct and separate entities featuring neuroendocrine differentiation, for which an accurate classification is clinically warranted. Materials and methods Three perspectives were addressed: (i) diagnostic tools, with the terminology to be used in either resection specimen or small-sized material; (ii) the so-called carcinoid tumors with elevated proliferation rates (mitotic and/or Ki-67 activity); (iii) predictive biomarkers based on immunohistochemical characterization. Results We herein provide a pathology update on lung neuroendocrine neoplasm classification that will appear in the forthcoming 5th edition of the WHO Blue Book, including a short discussion about biomarkers, which are presently given full consideration in clinical practice. Conclusion The WHO classification on lung neuroendocrine neoplasms is the cornerstone to provide the best clinical management of patients and is the starting point for any investigative insight.