ABSTRACT
Hard metal lung disease is a rare form of occupational lung disease that can occur
in workers engaged in the manufacture, utilization, or maintenance of tools composed
of hard metal [a material composed mainly of tungsten carbide (WC) and cobalt] or
diamond-cobalt. Clinically, the condition resembles hypersensitivity pneumonitis,
with subacute presentations and possible evolution to pulmonary fibrosis. However,
this interstitial lung disease is uniquely characterized by the presence of bizarre
``cannibalistic'' multinucleated giant cells in the alveoli and the bronchoalveolar
lavage. A pathological diagnosis of giant cell interstitial pneumonitis (GIP) is,
therefore, specific for hard metal lung disease, even though not all affected subjects
exhibit this pathognomonic feature. Cobalt is the critical toxic component causing
hard metal lung disease, hence also the term cobalt-lung. Hard metal lung disease is more likely to occur in poorly regulated workplaces, but
its occurrence depends mainly on individual susceptibility, rather than on cumulative
exposure, so that even young subjects may be affected.
KEYWORD
Cobalt - tungsten carbide - diamond
