Chyloptysis in adults: presentation, recognition, and differential diagnosis.

Chyloptysis is a rare finding, and the accompanying respiratory symptoms are usually nonspecific. The recognition of the chylous nature of the sputum is requisite for proper diagnosis, especially if chyloptysis is not accompanied by chylous pleural effusion. The key to the differential diagnosis of chyloptysis is to consider illnesses that can induce reflux of chyle into the bronchial tree. There are two mechanisms postulated: the first requires the presence of an abnormal communication between the bronchial tree and the lymphatic channels, and the second requires a bronchopleural fistula in the context of a chylous pleural effusion. Chyloptysis in adults should prompt assessment for evidence of lymphatic obstruction from trauma, radiation, and malignancy, and to exclude diseases with known association with chyloptysis, ie, lymphangioleiomyomatosis, yellow nail syndrome, or thoracic lymphangiectasis. A lymphangiogram is recommended to define the abnormality. In the case of lymphangiectasis, patients respond to either dietary modification and/or ligation of the thoracic duct.