Lung metastasis of transitional cell cancer of the urothelium, with fungus ball-like shadows closely resembling aspergilloma: A case report and review of the literature.

The present study reports the case of a 67-year-old female patient who was initially diagnosed with pulmonary aspergilloma. This diagnosis was based on a chest computed tomography (CT) scan showing a cavitary lesion of 3.5 cm in diameter, with fungus ball-like shadows inside, and an air crescent sign in the right upper lung. At 63 years old, the patient was treated for transitional cell cancer of the urothelium (non-invasive, pT1N0M0) by total cystectomy, ileal conduit diversion and urostomy. For 4 years post-operatively, the patient was healthy and had no clinical symptoms, and the air crescent sign was not identified by chest CT until the patient had reached 67 years of age. However, a final diagnosis of lung metastasis of transitional cell cancer of the urothelium was histopathologically identified subsequent to video-assisted thoracic surgery. Although it is rare that transitional cell cancer moves to the lung and makes a cavitary lesion, a differential diagnosis of cancer is necessary, even when examining infected patients with air crescent signs that are characteristic of aspergilloma. The physician must be mindful of metastatic pulmonary tumors that closely resemble aspergillomas, not only in infectious diseases, but also in oncological practice. Primary surgical removal should be considered.