The lungs in fatal measles infection in childhood: pathological, radiological and immunological correlations.

Multinucleated inclusion-bearing giant cells diagnostic of measles infection were identified in the pulmonary alveoli of seven children post mortem. Two children with leukaemia and a third with thymic dysplasia had prolongaed illness without typical measles exanthemata. All showed a striking proliferation of the respiratory epithelia, with formation of peribronchiolar fibro-epithelial nodules and cystic transformation of tracheo-bronchial glands. The nodular lesions contained many giant cells and were seen radiologically as multiple slowly-enlarging pulmonary opacities, a pattern which appears to be highly characteristic of measles infection in the presence of cellular immune deficiency. Two other children showed similar proliferative lesions, but had shorter illness with exanthemata and few tissue giant cells; these differences are attributed to the late appearance of a cellular immune response in less severe immune deficiencies. Two children who had no evidence of immune deficiencies died of acute viral alveolitis, one in the pre-exanthematous phase. Acute alveolitis was characterized radiologically by the rapid development of diffuse pulmonary opacification and by variable cytological features which correlated with other evidence for the presence or absence of a cellular immune response against the virus.