Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia: Unusual presentation.

Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNEC) is an abnormal proliferation of pulmonary neuroendocrine cells that occur without underlying etiology. Here, we report a unique case of 55-year-old female with unusual presentation of DIPNECH and thymoma and on the background history of Crohn's disease that might point toward an autoimmune phenomenon. To the best of our knowledge, there were no previous reports of DIPNECH with either thymoma or Crohn's disease. DIPNECH has premalignant potential and reported in association with carcinoid and non-small cell lung cancer; however, its autoimmune association never reported. The presence of multiple lung nodules along with evidence of small airway disease should alert the physician to include DIPNECH as part of the differential diagnosis given its malignant potential. The prognosis is variable and depends on the presence or absence of underlying malignancy as well as the severity of airflow obstruction.