[Atypical metastatic site of lung adenocarcinoma]

Lung adenocarcinoma with bladder metastasis: A case report and literature review

Background

Lung cancer is the most common cause of cancer-related mortality in the world. Unfortunately, more than 50% of patients have already metastasized at the time of diagnosis, contributing to morbidity and mortality. Common sites of metastasis are adrenal glands, liver, bone, and brain. Bladder metastasis is rare and should prompt a careful differential consideration of primary bladder cancer.

Case description

Here, we report a 72-year-old female who went to the hospital for "gross hematuria for one day". Cystoscopy showed space-occupying lesions in the bladder. During the general CT examination, space-occupying lesions in the lower lobe of the lung were found. Peripheral lung cancer with multiple lymph node metastases, pulmonary metastasis, and left pleural effusion were considered. Transurethral cystoscopic resection of the bladder tumor and pleural effusion cell block examination were performed to clarify the diagnosis. Combined with morphological and immunohistochemical results, both pathological results supported a diagnosis of lung adenocarcinoma metastasis, and gene detection was carried out. EGFR, ALK, and ROS-1 were negative. According to the genetic testing results, there was no corresponding targeted drug, so we administered chemotherapy, and one-year survival was achieved, which was better than expected based on other studies.

Conclusion

This paper describes a case of lung adenocarcinoma metastatic to the bladder and includes a review of the literature to provide clinicians with diagnostic and treatment experience and help avoid misdiagnosis and mistreatment.

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. The histopathological characteristics and immunohistochemical features of the patient are reported. It was proposed that pathologists should consider the possibility of metastatic adenocarcinoma from the lung, rather than assume a diagnosis of primary adenocarcinoma of the bladder or direct invasion of adenocarcinoma from the surrounding organs. Furthermore, it is essential to determine the medical history of each patient and observe the immunohistochemical features of all tumors prior to diagnosis.

Bladder metastasis from lung adenocarcinoma: a difficult differential diagnosis with primary bladder adenocarcinoma

BACKGROUND

Bladder metastases from lung adenocarcinoma are extremely rare; in the seven previously reported cases, the finding of an intact epithelium overlying the bladder tumour was considered suggestive of a secondary lesion. We describe the first case of bladder metastasis from lung adenocarcinoma whereby endoscopic appearance was strongly consistent with primary bladder cancer, thus complicating the differential diagnosis with primary bladder adenocarcinoma.

CASE REPORT

A 65-year-old woman with a 13-year history of clean intermittent catheterization was diagnosed with a right lung adenocarcinoma metastatic to mediastinal and right supraclavicular nodes, as well as to the left lung, and treated with six cycles of cisplatin/pemetrexed, followed by six cycles of pemetrexed only. The 18-month follow-up computed tomography revealed several solid lesions of the bladder wall and she was scheduled for transurethral resection of bladder tumours. Endoscopic appearance was strongly consistent with primary bladder cancer but a thorough pathologic evaluation allowed the diagnosis of bladder metastasis from lung adenocarcinoma.

CONCLUSIONS

Differentiating primary bladder adenocarcinoma from metastatic adenocarcinoma lesions can be difficult. An endoscopic appearance consistent with primary bladder cancer further complicates the differential diagnosis, which heavily relies on pathologic evaluation and specific immunohistochemical staining.

A rare metastasis to the bladder

Primary bladder cancer is the fifth most common malignancy but secondary malignancies of the bladder are rare. Distinguishing primary adenocarcinomas of the bladder from secondary adenocarcinomas is difficult and relies on immunohistochemical staining. Prostate, colorectal, breast, and lung all can produce metastatic adenocarcinomas to the bladder. Further management of the malignancy varies depending on the source, thus making proper diagnosis critical. We present only the fifth documented case of metastatic adenocarcinoma of the lung to bladder and performed a review of the literature.