TALC- (hydrated magnesium silicate)

AJR Am J Roentgenol. 1986 Feb;146(2):295-301.

Talc: understanding its manifestations in the chest.

Feigin DS.

Abstract

Four distinct forms of pulmonary disease caused by talc have been defined. The first form, talcosilicosis, is caused by talc mined with high-silica-content mineral. Findings in this form are identical with those of silicosis. Talcoasbestosis closely resembles asbestosis and is produced by crystalline talc, generally inhaled with asbestos fibers. Pathologic and radiographic abnormalities are virtually identical with those of asbestosis, including calcifications and malignant tumor formation. The third form, talcosis, caused by inhalation of pure talc, may include acute or chronic bronchitis as well as interstitial inflammation; radiographically, it appears as interstitial reticulations or small, irregular nodules, typical of small-airway obstruction. The fourth form, due to intravenous administration of talc, is usually associated with abuse of oral medications and production of vascular granulomas manifested by consolidations, large nodules, and masses. Radiographic abnormalities associated with talc can be predicted when there is sufficient history of the nature of exposure, including the region of origin of the talc in cases of inhalation. Radiographic changes, such as diaphragmatic plaques, often attributed to both talc and asbestos have not been documented to be caused by talc alone. The author provides review of 18 well-documented cases.

(COMMENT: still used in some baby powders).