Pulmonary aspergilloma with renal oxalosis: fatal effect at a distance.

Some species of the fungus Aspergillus, especially Aspergillus niger, produce oxalic acid as a fermentation byproduct. The acid combines with calcium ions at physiological pH to form insoluble calcium oxalate crystals that are mainly deposited at local sites. This is often seen in the lungs, where the crystals tend to potentiate the destructive capacity of the fungus. In rare instances, there is hyperoxaluria and deposition of the crystals in the renal tubules. We report this rare occurrence in a 59-year-old man with pulmonary aspergilloma and acute renal failure. To the best of our knowledge, this is the fifth case to be reported.