余秉軒¹、魏子鈞^1,2,3、鍾孝仁^1,2,3、黃志賢^1,2,3

台北榮民總醫院泌尿部¹；國立陽明大學醫學系泌尿學科²；書田泌尿科學研究中心³

Ping-Hsuan Yu¹, Tzu-Chun Wei^1,2,3, Hsiao-Jen Chung^1,2,3, William J.S. Huang^1,2,3

¹ Department of Urology, Taipei Veterans General Hospital

² Department of Urology, School of Medicine, National Yang-Ming University

³Shu-Tien Urological Science Research Center, Taipei, Taiwan

 

Metastatic lesions at bladder are less common than bladder primary urothelial carcinoma. Among these metastatic lesions, melanoma, breast cancer and gastric cancer are possible origins. Here we present a case of gastric adenocarcinoma with bladder metastasis after disease free for four years.

 

A 64-year-old female was diagnosed with gastric cancer in 2014. She has an underlying disease of mitral valve prolapse, otherwise no other systemic diseases such as hypertension and diabetes mellitus. The first presentation of gastric cancer was easy satiety and the diagnosis was made by endoscopic biopsy. The staging by computed tomogram before the surgery was cT2N0M0. She underwent surgeries including radical total gastrectomy and Roux-en-Y esophagojejunostomy on 2014/05/02. The pathology revealed gastric adenocarcinoma, pT3N2. Six lymph nodes were positive for cancer out of the 35 harvested lymph nodes. Chemotherapy with capecitabine and oxaliplatin was performed for a total of 12 doses after the surgery. After the systemic therapy was completed, she was under regular follow-up at medical oncology outpatient clinic. The disease could not be detected in image follow-up.

 

However, regular abdominal sonogram for gastric cancer follow-up on 2018/11/30 showed focal thickening of urinary bladder anterior wall with thickness of 1.35 cm. Thus, the patient was referred to urology clinic for further evaluation. At urology clinic, the patient complained about symptoms including voiding discomfort, nocturia about 5 times per night, incomplete emptying and incontinence. She denied frequency, urgency, or gross hematuria. Urinalysis did not show microscopic hematuria or pyuria. Urine cytology was negative for malignant cells. Blood test disclosed generally normal hematological and biochemical data. Tumor markers are also within normal limits, including CEA: 2.5ng/ml and CA-199: 9.15u/ml. To examine the lesion, cystoscopy was performed on 2019/01/07. Multiple polypoid lesions were observed at anterior bladder wall in this study. We performed biopsy and the pathology showed papillary urothelial hyperplasia. The microscopic findings showed sections with tenting, undulating and papillary protrusion of urothelium without formation of true papillary fronds. Urinary bladder wall lesion cannot be well evaluated in the computed tomogram due to inadequate opacification of urinary bladder. No local recurrence or enlarged lymph node was noticed in computed tomogram.

 

Although the pathology of cystoscopic biopsy showed benign results, malignancy could not be thoroughly ruled out under serial surveys mentioned above. After discussion with this patient, further operation to clarify the entity of this bladder lesion was indicated. We had the patient admitted to urology ward on 2019/01/22. Transurethral resection of bladder tumor (TURBT) was performed on 2019/01/23. Intra-operative findings revealed the adenoma-like lesion near dome. Surprisingly, the pathological report disclosed metastatic adenocarcinoma. Poorly differentiated adenocarcinoma, with mostly signet ring cells, in the lamina propria could be observed microscopically. Morphologically, it is compatible with metastatic gastric adenocarcinoma.

 

Since gastric adenocarcinoma recurrence with distant metastasis was diagnosed, the patient came back to oncology clinic. The oncologist offered the patient chemotherapy with docetaxel and ramucirumab, and the first dose was given on 2019/03/17. The patient complained irritative symptoms such as frequency at urology clinic follow-up, but the symptoms could subside under anti-muscarinic agents.

 

Bladder tumors secondary to other organs are mostly from adjacent pelvic organs, such as prostate, colon, or gynecological organs by direct invasion. As for distant metastasis, melanoma, breast cancer, and gastric cancers are more common primary cancers. Reviewing related literatures, most papers involving bladder metastasis secondary to gastric cancer are case reports with only one to three patients in each literature. Gross hematuria and irritative symptoms are common symptoms at diagnosis within these cases. Signet-ring cell is histologically more common in tumors of gastrointestinal tract. Immunohistochemical stains may help to differentiate primary bladder signet-ring cell adenocarcinoma from signet-ring cell adenocarcinoma of gastric origin. Chemotherapy and radiotherapy can help disease control, and VEGFR 2 inhibitor can also be used in such circumstances.