Lung Metastasis of Ta Bladder Cancer: A Case Report and Literature Review
A 66-year-old man had been diagnosed with Ta bladder cancer 6 years before he complained of dry cough in July 2009. He had a history of recurrent non-muscle-invasive bladder tumors and had therefore undergone 7 transurethral resections (TURs) and had received intravesicular chemotherapies (8 cycles of weekly mitomycin-C after the 4th TUR and 5 cycles of biweekly pirarubicin after the 5th TUR). All tumors were <1 cm, well pedunculated, and papillary. The number of tumors ranged from 1 to 6 in each respective TUR. The pathological findings of all TURs indicated the presence of urothelial carcinoma (stage Ta without carcinoma in situ, grade 1 or 2) without lymphatic or vascular invasion. The last TUR in January 2009 showed the same findings as the previous TURs, i.e., there were 3 tiny papillary tumors located at the right lateral wall, at the posterior wall, and adjacent to the left ureteral orifice, and pathological examination indicated results similar to those of the previous TURs. Chest radiography at 6 months after the last TUR detected a round nodule (diameter, 7.5 cm) in the right lower lung. We carefully rechecked the chest radiograph obtained in April 2008, which showed a small nodule (diameter, 1 cm) in the same area. These observations suggest that the lung metastasis had occurred more than 1 year previously. The initial diagnosis based on the computed tomography findings was primary lung cancer (). Therefore, initial treatment consisted of video-assisted thoracoscopic lobectomy. The histopathologic features of the pulmonary lesion and the TUR specimen of the bladder cancer were qualitatively similar. Immunohistochemistry showed that both the TUR specimen and the pulmonary lesion were positive for the urothelium-specific protein uroplakin Ia (UP-Ia) [] (). On the basis of these findings, the patient was diagnosed with pulmonary metastasis of recurrent Ta bladder cancer. Subsequently, he received 2 cycles of postoperative chemotherapy with the same gemcitabine and cisplatin regimen reported by von der Maase et al. []. Although we had planned 3 cycles of chemotherapy, the patient refused the third course. His bladder cancer recurred at 3 and 8 months after chemotherapy and hence he underwent TUR both times. The results of the pathological examination were the same results as for the previous TURs. Two and a half years after chemotherapy, chest and abdominal computed tomography once every 3 months detected no recurrence of the pulmonary lesions or other distant metastasis.