A case of pulmonary tumor embolism presenting with an initial manifestation of urothelial carcinoma

: A 64-year-old man presented with fever, chest pain, and bloody sputum. Chest computed tomography showed multiple, irregularly shaped infiltrative shadows in the subpleural regions of both lung fields. Out of the 6 sputum cytology specimens, only one specimen suggested malignancy. Furthermore, no malignant cells were detected in the bronchoalveolar lavage fluid. A video-assisted lung biopsy yielded a diagnosis of pulmonary tumor embolism was made. The primary lesion of this pulmonary metastatic cancer was urothelial carcinoma, which was not detected by contrast-enhanced computed tomography of the abdomen. This case is particularly unusual because it is difficult to establish an ante-mortem diagnosis of pulmonary tumor embolism, and there have been only a few previous reports regarding pulmonary tumor embolism from a urothelial tumor.