Tissue Procurement and Natural History Study of People With Non-Small Cell Lung Cancer, Small Cell Lung Cancer, Extrapulmonary Small Cell Cancer, Pulmonary Neuroendocrine Tumors, and Thymic Epithelial Tumors

Background: * Lung cancer is the leading cause of cancer-related death worldwide, accounting for more than one million deaths every year. * Several genetic and epigenetic alterations are involved in initiation and progression of NSCLC. Some of these alterations are seen in normal and pre-neoplastic cells as well, suggesting a sequential development from normal epithelial cells to cancer, through a multistep process, usually coincident with cigarette smoking. * This natural history protocol is an extension of our Molecular Profiling protocol to enable tissue collection for more in-depth proteomic and genomic analyses to understand tumor biology and treatment response. * A cohort of patients enrolled in this natural history study is likely to enroll in the IRB approved protocol for end-of-life in-patient hospice and rapid autopsy following death (13-C-0131). Longitudinally collected tumor tissue from these patients, including from several metastatic sites at autopsy will be a unique resource to understand tumor evolution. * There will be opportunity to embark upon a wide array of studies in the future with the longitudinally collected tissue samples tagged with clinical information from patients. Objectives: \- To allow sample acquisition for use in the study of non-small cell lung cancer (NSCLC), Small cell lung cancer (SCLC), extrapulmonary small cell cancer (ESCC), pulmonary neuroendocrine tumors (PNET), and thymic epithelial tumors (TETs). Eligibility: * Patients with histologically or cytologically confirmed NSCLC, SCLC, ESCC, PNET, and TET. * Patients consulted in the Clinical Center without a definitive diagnosis, but clinically considered likely to have a thoracic malignancy of the above histologies, pending further tissue acquisition and/or pathology review. * Age greater than or equal to 18 years. Design: * This is a biospecimen collection and natural history protocol in which samples will be collected from patients with NSCLC, SCLC, ESCC, PNET, and TET. * Eligible patients undergoing screening for or participating in NIH protocols or eligible patients treated elsewhere and referred from other oncologists will be referred for participation in this study. * Upon providing informed consent, patients will undergo sample acquisition procedures, which may include a tumor biopsy, bone marrow biopsy or the collection of blood, urine or other body fluids. * An accrual ceiling of 2000 subjects is planned.