Melanoptysis: findings on CT and MRI

The purpose of this study was to demonstrate the CT and MRI features of liquefied progressive massive fibrosis (PMF) in coal worker's pneumoconiosis (CWP). A retrospective analysis was made of the CT and MRI features in five patients suffering from severe CWP with the initial clinical finding of melanoptysis ("black phtisis"). CT showed either an air-fluid level or a fluid-precipitate level with high density in the dependent layer. On pre-contrast T-1 weighted images, liquefied PMF showed a fluid level with isointensity relative to soft tissue in the upper layer and a signal loss in the dependent layer of the lesion. The wall of the PMF showed rim enhancement after administration of iv gadolinium. On T-2 weighted images there was a high signal intensity in the upper layer of the lesion. In conclusion, liquefied PMF results in characteristic features on CT and MRI owing to precipitation of silica in the mucous fluid.