Pulmonary migratory infiltrates due to mycoplasma infection: case report and review of the literature.

Pulmonary migratory infiltrates (PMI) are observed in a few diseases. We report here a case of PMI attributed to Mycoplasma pneumonia (Mp) infection. The patient's past medical history was characterized by fleeting and/or relapses of patchy opacification or infiltrates of parenchyma throughout the whole lung field except for left lower lobe radiographically. Serological assays revealed an elevation of IgG antibody specific to Mp and its fourfold increase in convalescent serum. Histopathological findings showed polypoid plugs of fibroblastic tissue filling and obliterating small air ways and interstitial infiltrates of mononuclear inflammatory cells in the vicinal alveolar septa. The patient was treated with azithromycin which resulted in a dramatic improvement clinically and imageologically. In spite of the increasing incidence of Mp, the possible unusual imaging manifestation and underlying mechanism haven't attracted enough attention. To our knowledge, there are rare reports of such cases.