Bilateral Hydronephrotic Bladder Metastasis from Lung Cancer.

A 61-year-old man who had lung adenocarcinoma stage IIIA, cT3N1M0, with an epidermal growth factor receptor (EGFR) mutation in exon 19, and who had been treated with chemotherapy presented with left hydronephrosis. The etiology was unknown. The cystoscopy findings were normal. The hydronephrosis improved after placing a ureteral stent, but it recurred with increased bladder wall thickness (Picture). Cystoscopy was thus performed a second time and a bladder mucosa projection was observed that was later found to be adenocarcinoma with an EGFR mutation, but without a T790M mutation. This was therefore thought to be lung adenocarcinoma metastasis. After the patient's death, autopsy revealed increased bladder wall thickness and a small cavity. Histologically, there were numerous tumor cells under the intact urothelial epithelium.

Picture.

Bladder metastasis from lung cancer is rare (1). One of the few reported cases had a normal cystoscopic appearance (2). Our case implies that bladder metastasis should therefore be considered when a patient with lung cancer develops hydronephrosis.

The authors state that they have no Conflict of Interest (COI).