Bladder metastasis from epidermal growth factor receptor mutant lung cancer: A case report

BACKGROUND: Bladder metastasis from lung cancer with epidermal growth factor receptor (EGFR) mutation is extremely rare. Here, we report a case of bladder metastasis from lung adenocarcinoma with EGFR mutation. CASE SUMMARY: A 53-year-old female patient was diagnosed with advanced lung adenocarcinoma with EGFR exon 19 deletion. Multiple nodules on the bladder wall were found by regular examination of the pelvic cavity through computed tomography during targeted therapy. Further cystoscopy and histological examination of bladder biopsy tissues confirmed the bladder metastasis from lung adenocarcinoma. In addition, genetic analysis of the bladder metastasis revealed EGFR T790M mutation. The patient achieved a good response to a third-generation EGFR tyrosine kinase inhibitor. CONCLUSION: During routine follow-up of lung cancer patients, imaging examination of the pelvic cavity should be performed to avoid missing bladder metastasis. The ultimate diagnosis of bladder metastasis sill depends on the pathological result of biopsy tissues.