Investigation of Nigerians with diffuse radiographic pulmonary shadowing.

During a five-year period, 45 Nigerians with radiographic appearances of diffuse pulmonary infiltration with at least six sputum specimens negative on culture for tubercule bacilli were investigated at University College Hospital, Ibadan. The value of pulmonary function studies and open or closed lung biopsy in discovering the cause of diffuse lung disease was examined. Cryptogenic fibrosing alveolitis was the most common cause (13 cases). Other diagnoses included malignant disease (11 cases), sarcoidosis (three cases), progressive systemic sclerosis (three cases), miliary and non-caseating tuberculosis (three cases) and pulmonary alveolar microlithiasis (one case): this last is believed to be the first case diagnosed in Africa South of the Sahara. This study emphasizes the fact that, even in developing countries where tuberculosis is highly prevalent, there are other causes of diffuse pulmonary infiltration.