Progressive massive fibrosis (PMF) refers to the formation of large mass-like conglomerates, predominantly in the upper pulmonary lobes, associated with radiating strands. The areas classically develop in the context of certain pneumoconioses (especially coal worker’s pneumoconiosis and silicosis) although similar mass-like densities have occasionally been described with talcosis.
https://radiopaedia.org/articles/progressive-massive-fibrosis