Pulmonary Neuroendocrine Neoplasms

Pulmonary neuroendocrine neoplasms (NENs) are a heterogeneous group of tumors of the neuroendocrine cells, which are diffusely interspersed throughout the respiratory system. Two families of NEN are established according to histological grading: the well-differentiated neuroendocrine tumors (NETs) and the high-grade neuroendocrine carcinomas (NECs). Four types of NEN are recognized, including two NETs represented by typical carcinoid (TC) and atypical carcinoid (AC) and two NECs represented by large cell neuroendocrine carcinoma (LCNEC) and small cell lung carcinoma (SCLC).