Giant cell interstitial pneumonia associated with occupational iron exposure: an exceptional case report.

Multinucleated giant cell pneumonia associated with heavy metals (GIP) is a rare disease of the pulmonary parenchyma, with just over one hundred cases reported in the scientific literature. It has been associated almost exclusively with occupational exposure to tungsten and cobalt. Although its pathogenesis is not fully understood, it has been proposed that exposure to an aetiological agent, together with an immune imbalance, underlies the pathophysiology of the characteristic microscopic findings, including fibrosis, multinucleated foreign-body giant cells and cannibalism. To date, iron has not been described as one of the causative agents. We present the case of a 41-year-old patient with documented occupational exposure to iron who developed respiratory failure. For the first time, findings consistent with GIP were demonstrated in the pulmonary parenchyma, with microscopic features that we consider specific.