Spectrum of pulmonary neuroendocrine cell proliferation: diffuse idiopathic pulmonary neuroendocrine cell hyperplasia, tumorlet, and carcinoids.

OBJECTIVE: The objectives of this article are to review the radiologic, pathologic, and clinical features of diffuse idiopathic pulmonary neuroendocrine cell hyperplasia, tumorlet, and carcinoids and to discuss the possible role of diffuse idiopathic pulmonary neuroendocrine cell hyperplasia and tumorlet in the development of carcinoids. CONCLUSION: Given the potential significant morbidity of diffuse idiopathic pulmonary neuroendocrine cell hyperplasia and its neoplastic counterparts, it is important to understand and recognize these disease entities. A conceptual continuum of these neuroendocrine entities is suggested.