Saprophytic invasion of infarcted pulmonary tissue by Aspergillus species.

Saprophytic invasion of infarcted pulmonary tissue has received only passing reference in published reports. Five patients with colonisation of pulmonary infarcts by aspergillus are described, with discussion of the clinical and histopathological features. The characteristic features were widespread invasion of dead tissue by fungal hyphae, in three cases with liquefaction resulting in the production of a cavitated lesion. There was no evidence that the vascular thrombosis and the consequent infarction present in four cases were caused by the fungus. In two cases the lesions were resected as possible peripheral cavitated tumours, and in two they were incidental findings at necropsy in patients who had had carcinoma and received radiotherapy. In the fifth case the clinical diagnosis was pneumococcal pneumonia but the possibility of primary aspergillus pneumonia was raised.