Sometimes the inflammatory reaction is mainly one of scarring, as seen here with a silicotic nodule of the lung. The inhaled silica persists indefinitely and produces an inflammatory reaction with ongoing production of cytokines that is marked by prominent fibrosis. The nodule is composed mainly of dense pink collagen. Though there is minimal inflammation, the process is slow and progressive and can diminish (restrict) lung capacity, leading to worsening dyspnea.