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).\r\n\r\nThese malignancies show different morphological, immunohistochemical, molecular, and imaging features. Such heterogeneity is reflected by extremely different clinical and biological behaviors, ranging from the indolent course of TC to the highly aggressive behavior of SCLC.\r\n\r\nThis chapter provides a detailed overview on the epidemiologic and histologic features of the pulmonary NENs, including staging, prognostic, and therapeutic aspects. Noteworthy, the chapter will focus on imaging characteristics of NENs, with detailed description of thoracic (local and nodal involvement) and extrathoracic diffusion pathways.