Pulmonary Aspergillus niger Fungus Ball Associated with Calcium Oxalate Crystal: A Case Report

ABSTRACT

Pulmonary aspergillomas are considered to represent saprophytic growth of hyphae within the preexisting lung cavity. Causative Aspergillus species are mostly composed of A. fumigatus and A. flavus and, occasionally, A. niger. It is difficult to identify these species using histopathologic evaluation without a culture of sputum and bronchoalveolar lavage. We recently experienced a case of pulmonary Aspergillus niger infection associated with characteristic calcium oxalate crystal formation. A large cavity contained hyphae with a typical conidial head, conidiophore, and conidia. Characteristic birefrigent calcium oxalate crystals were demonstrated in the cavity wall.