Isolated bladder metastasis from lung adenocarcinoma: a case report.

Cancers of extra bladder origin represent between 2 and 12% of bladder neoplasms and are most often secondary to contiguous bladder invasion. Metastasis from distant organs is exceptional, especially from pulmonary adenocarcinoma with <10 cases identified over the last 20 years. We report here a new case of a 55-year-old patient with a recently diagnosed pulmonary adenocarcinoma referred to the urology department for macroscopic hematuria. Computed tomography scan showed, in addition to the lung mass of the right lower lobe with a right mediastinal adenopathy, a thickening of the right lateral bladder wall. Cystoscopy showed inflammatory lesions on the bladder mucosa, which biopsy with immunohistochemical examination revealed to be tumoral proliferation in the lamina propria realizing the same immunohistochemical profile of the primary lung tumor (CK7+/TTF1+/CK20-/PSA-). The patient was treated with palliative platinum-based chemotherapy and unfortunately died 5 months after diagnosis.