Cushing's Syndrome Caused by Corticotropin Secretion by Pulmonary Tumorlets

Abstract
The term “pulmonary tumorlets” describes multiple microscopic nests of neuroendocrine cells in the lungs.1 Like bronchial carcinoid tumors and small-cell carcinomas, pulmonary tumorlets arise from Kulchitsky's cells. In the lung the abnormalities in these cells range from hyperplasia to malignant transformation, since control over cellular growth is lost.2