Metastatic lung adenocarcinoma to the bladder: A case report.

Urothelial cancer is the most frequently diagnosed type of malignant tumor in the bladder, of which primary adenocarcinoma accounts for a small percentage. Secondary malignancies, in particular metastatic adenocarcinoma from the lung, are exceedingly rare, with only six cases previously reported in the literature. The present study describes the case of a 71-year-old Chinese male patient with known lung cancer for >2 years, who was diagnosed with metastatic adenocarcinoma to the bladder.