Giant cell interstitial pneumonia.
 Giant cell interstitial pneumonia is a distinctive and uncommon form of interstitial pneumonia.
 It is distinguished by the prominence of large, actively phagocytic alveolar giant cells of histiocytic origin in the presence of chronic interstitial pneumonia.
 Multinucleated type 2 granular pneumocytes are also identified.
 The multinucleated cells lack viral intranuclear inclusions of the type seen in measles pneumonia.
 Giant cell interstitial pneumonia may be idiopathic or it may occur with occupational exposure to hard metals or cobalt.
 We report this case to give recognition to an uncommon interstitial pneumonia.
