|Year : 2013 | Volume
| Issue : 1 | Page : 151-153
Small cell carcinoma of the urinary bladder diverticulum: A case report and review of the literature
Wu Xu Dong1, Yan Xiao Ping1, Wang Chen Liang2, Li Zhi Jian1, Zhang Ji Lin3
1 Department of Urology, First people's Hospital of Jiujiang City, Jiangxi Province, China
2 Department of Pathology, First people's Hospital of Jiujiang City, Jiangxi Province, China
3 CT Room, First people's Hospital of Jiujiang City, Jiangxi Province, China
|Date of Web Publication||10-Apr-2013|
Wu Xu Dong
Department of Urology, First people's Hospital of Jiujiang City, Jiangxi Province
Source of Support: None, Conflict of Interest: None
Small cell carcinoma of the urinary bladder is very rare. Small cell carcinoma of the urinary bladder is a mass with swiftly aggressive and metastatic, and with a poor prognosis. Due to its scarcity, no forward-looking researches assessing the most effective treatment have been issued in the medical literature. It can happen either in connection with urothelial (transitional cell) carcinoma or in a pure form. Its treatment should include surgery, chemotherapy and radiotherapy. In this article,we report a case occurring in a mixed form in the urinary bladder diverticulum and we concisely review the published literature with respect to the clinical manifestation, pathology,differential diagnosis, treatment and prognosis.
Keywords: Small cell carcinoma, Treatment and Prognosis, Urinary bladder diverticulum
|How to cite this article:|
Dong WX, Ping YX, Liang WC, Jian LZ, Lin ZJ. Small cell carcinoma of the urinary bladder diverticulum: A case report and review of the literature. J Can Res Ther 2013;9:151-3
|How to cite this URL:|
Dong WX, Ping YX, Liang WC, Jian LZ, Lin ZJ. Small cell carcinoma of the urinary bladder diverticulum: A case report and review of the literature. J Can Res Ther [serial online] 2013 [cited 2019 Aug 22];9:151-3. Available from: http://www.cancerjournal.net/text.asp?2013/9/1/151/110372
| > Introduction|| |
Small cell carcinoma is usually diagnosed in the lung but its extrapulmonary counterpart is infrequently met. Small cell carcinoma of the urinary bladder is remarkably rare and accounts for less than 0.7% of all the urinary bladder.  Nevertheless, small cell carcinoma occured in a bladder diverticulum has been recounted in only 6 cases in the documents.  Small cell carcinoma of the urinary bladder is an epithelial tumor related with a more aggressive behavior and poorer prognosis than transitional cell bladder carcinoma. we presented a new case of this rare tumor and a relevant literature review.
| > Case Report|| |
A 50-year-old man showed gross painless intermittent hematuria with a 2-month history in April 2009. Urinalysis disclosed countless erythrocytes. Abdominal CT scan exhibited a irregular solid lesion in a bladder diverticulum located on the left lateral bladder wall [Figure 1]. Cystoscopy confirmed this finding. but biopsy did't prompted meaningful results before surgery. we referred to the treatment standard of bladder transitional cell carcinoma. So a partial cystectomy was executed and the tumor was cut out along a 1 cm circumferential margin.
|Figure 1: Abdominal CT scan revealed a irregular solid mass in a bladder diverticulum located on the left lateral bladder wall|
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Histopathologyical examination showed outstanding sheets and nests of a uniform population of small round cells. The distinction between the dominant small round cell component and the focal urothelial (transitional) cell carcinoma was apparent on H and E stained sections [Figure 2], indicating a mixed high-grade malignant tumor. In immunohistochemical staining, the dominant small round cell component expressed synaptophysin [Figure 3] and CD56 [Figure 4], manifesting a neuroendocine differentiation. Hence, a diagnosis of a primary mixed small cell carcinoma was confirmed. We recommended chemotherapy, but unfortunately the patient refused.
|Figure 2: Predominance of sheets and nests of a uniform population of small round cells were seen. The distinction between the predominant small round cell component and the focal urothelial (transitional) cell carcinoma was apparent (H and E, × 400)|
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|Figure 3: The predominant small round cell component expressed synaptophysin (Syn) (× 400)|
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|Figure 4: The predominant small round cell component expressed CD56 (× 400)|
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After 5 months, recurred cancer appeared postoperative. A CT scan of the abdomen and pelvis showed a solid mass located in the left lateral bladder wall and a left pelvic limph node involved. Patient was treated with 1 cycles of cisplatin and etoposide preoperative and performed by radical cystectomy, left pelvic limph node resections and urinary derivation. The patient was then treated with 4 cycles of cisplatin and etoposide after surgery, as well as radiaotherapy with 50 Gy. Both postoperative immunostaining examination showed carcinous cells expressed markers of neuroendocine differentiation, including synaptophysin and CD56. The final pathology results from the radical cystectomy specimen demonstrated small cell carcinoma with a clinical stage T4. The patient was dead 29 months later after being diagnosed with metastases to liver.
| > Discussion|| |
Best of our knowledge, pulmonary SCC is a scarcity but well-characterized entity. Primary SCCB is a rare disease and its pathogenesis was ambiguous. However, the multipotent stem cell theory applies optimally to this case. Bceause it may explain the coexistence of SCCB with urothelial (transitional) cell carcinoma, and the different components of the immunohistochemical staining. So, our research results support the multipotent stem cell theory.
Painless gross hematuria was the most usual presenting symptom in SCCB owing to a large polypoid ulcerated and extremely invasive tumor. , Dysuria has been reported as the second most common symptom.  The tumor was inclined to be located on the lateral bladder wall (15.7%), on the posterior bladder wall (8%).  we presented the case that hematuria appeared initially and tumor located on the left lateral bladder wall.
On light microscopy, small cell carcinoma is composed of small round or oval shaped cells, with a projected nucleus, insufficient cytoplasm and granular chromatin. Tumors is consisted of nests of small round malignant cells.  Immunohistochemistry was considered to be beneficial for SCCB diagnosis. Because carcinous cells expressed markers of nenroendocrine differentiation including chromogranin, NSE (neurone specific enolase) and synaptophysin.  In the vast majority of reported cases, authors showed a higher incidence of mixed small cell carcinoma. , In our present case, the patient had mixed histology.
The common locations of SCCB metastasis were the retroperitoneal lymph nodes, the liver, the lung, the bone, and the brain. , Bladder tumors originated from a diverticulum are uncommon. In contrast to the normal bladder wall, deficiency of muscle fibers in the diverticulum makes it difficult to distinguish the tumors into superficial and invasive bladder cancer. Moreover, the scarcity of muscle fibers theoretically makes the cancer cell to encroach early and easily. 
Small cell carcinoma of the bladder must differentiate histologically from the bladder invasion of metastatic SCC or lymphoma. Metastatic SCC from other source, usually from the lung, may not be distinctive histologically from a primary SCCB; But, the existence of transitional cell carcinoma component would support a primary source in the bladder. Distinguish of SCC from lymphoma may be possible by immunohistochimestry. Lymphoma shows positive immunostaining for lenkocyte common antigen (LCA) and negative immunostaining for keratin and neuroendocrin markers. 
Due to the poverty of prospective studies, the optimal treatment of SCCB can not be instituted. In a multi-institutional review of 64 patients with a muscle invasive disease, a multivariant analysis showed that neither chemotherapy nor radiation, nor surgery had any effect on overall survival.  Surgey alone, including radical resection, partial cystectomy or the transurethral resection, is not adequate to obtain cure for patients with limited stage. A retrospective study of 46 patients remedied at the M.D.Anderson cancer revealed a 5-year survival of 78% for patients undergoing neoadjuvant chemotherapy followed by cystectomy, versus 36% for patients receiving cystectomy alone.  For localized primary SCCB, a complex treatment including surgery, chemotherapy and radiotherapy, is essential to achieve long-term disease free and overall survival. For metastatic tumor,the chemotherapy using a platinum agent is the main treatment. 
One thing was clear that small cell carcinoma of urinary bladder could happen easily system transfer, so surgical treatment alone was not enough and adjuvant therapy should be considered. Patients received adjuvant chemotherapy or radiotherapy than simple surgery had significantly improved the prognosis of patients statistically.  We used a combination of cystectomy with left pevlic lymph node dissection and adjuvant chemotherapy and radiotherapy. All of these ways make the patient successfully survival 29 months. So, we think that treatment of small cell carcinoma of the bladder requires a multidisciplinary approach.
| > References|| |
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[Figure 1], [Figure 2], [Figure 3], [Figure 4]