Pulmonary neuroendocrine tumors: What (little) do we know?

Pulmonary neuroendocrine tumors are a distinct subset of tumors composing approximately 20% of all lung cancers. The major categories of pulmonary neuroendocrine tumors include typical and atypical carcinoids, large cell neuroendocrine carcinoma, and the more common small cell lung cancer. They are classified into different categories in the 2004 World Health Organization system, but share structural and morphologic features. Despite these shared features, their clinical characteristics range from indolent to aggressive, and therefore the approach to treatment depends on the histologic subtype. This article discusses the current understanding of the epidemiology, pathologic characteristics, treatment, and prognosis of this spectrum of diseases.