Abstract
BACKGROUND: Spontaneous regression of lesions occurs in non-infectious benign diseases, such as sarcoidosis, as well as in infectious diseases, such as tuberculosis. Lung cancer and malignant lymphoma, on the other hand, rarely follow a similar course. We report a rare case of lung tuberculosis that presented with multiple nodules with metachronous changes in size. CASE PRESENTATION: We describe the case of a 50-year-old immunocompetent Japanese man with pulmonary tuberculosis in the form of multifocal nodules. He came to our hospital because of a chest X-ray abnormality. During the course of observation, some nodules reduced while others enlarged in size. Two years after the first visit, fever and pleural effusion appeared. The sputum examination turned out to be positive for tuberculosis. A course of anti-tubercular agents resolved the pleural effusion and multifocal nodules. CONCLUSION: Differences in the manner of granuloma formation suggest that the local immune response can be different even in the same lung field.