Cavitary lung metastases of mixed metaplastic breast cancer mimicking aspergilloma.

We report a case of a 57-year-old woman with pulmonary metastasis of breast cancer presenting with a characteristic cavitary shadow resembling aspergilloma. The primary tumor and metastases showed multiple histopathologic components, including squamous cell carcinoma. Although a fungal ball-like shadow may indicate the presence of a pulmonary aspergilloma, a comprehensive examination, including bronchoscopy, should be considered.