Bladder metastasis from gastric cancer presenting as acute post-renal obstruction during immunotherapy: a case report

By
Jiaojiao Hou
Xiaolei Yin
Lili Mi
Xin Han
Ning Li
Fei Yin
June 30, 2026
0 min

Frontiers In Oncology

Overview

This case study presents a rare instance of bladder metastasis from gastric cancer, leading to acute post-renal obstruction during immunotherapy. The patient experienced significant complications, including acute kidney injury and progressive obstructive uropathy.

Background

Bladder metastasis from gastric cancer is exceedingly rare and often misdiagnosed. Early identification of such metastases is crucial, as delayed diagnosis can lead to irreversible renal damage. Understanding the diagnostic challenges associated with immunotherapy is essential for improving patient outcomes.

Data Highlights

No numerical data or trial data were presented in the article.

Key Findings

Bladder metastasis from gastric cancer can present as acute post-renal obstruction.
Immunotherapy may complicate the clinical evaluation of new urinary symptoms.
Cystoscopy and targeted biopsy are critical for distinguishing between immunotherapy-related toxicity and metastatic disease.
The patient developed bilateral hydronephrosis and acute kidney injury despite initial response to treatment.
Histopathological examination confirmed poorly differentiated adenocarcinoma with signet-ring cell features.

Clinical Implications

Early cystoscopy and biopsy can facilitate timely diagnosis and management in patients with gastric cancer who develop new urinary symptoms during immunotherapy.

Conclusion

This case highlights the importance of distinguishing between immunotherapy-related adverse events and metastatic disease in patients with gastric cancer.