CASE REPORT Non Functioning Paraganglioma in the Urinary Bladder: A Case Report Shangren Wang1, Aiqiao Zhang1, Shiqiao Huang2, Yong Ma2,*, Yongjiao Yang1, Xiaoqiang Liu1 , Ludong Zhang2 1Department of Urology, Tianjin Medical University General Hospital, Tianjin, 300052, China. 2Department of Urology, Shanxian Central Hospital, Heze 274300, China. *Correspondence: Department of Urology, Tianjin Medical University General Hospital, Tianjin, 300052, China. E-mail: xiaoqiangliu1920@126.com Received August 2018 & Accepted January 2019 Paragangliomas are tumors that arise from autonomic nervous system. Non-functioning bladder paraganglioma is rare and usually misdiagnosed. Here we describe a case of a 45-year-old man with primary urinary bladder para- ganglioma. The patient had no active signs and symptoms, and histological and immunohistological examinations of a transurethral resection specimen confirmed correct diagnosis. After successful transurethral resection of the tumors, the patient showed no signs of recurrence at one-year follow-up. Keywords: pheochromocytoma; non-functioning paraganglioma; urinary bladder INTRODUCTION Primary urinary bladder paraganglioma is a rare neoplasm that develops from the chromaffin tissue of the sym-pathetic nervous system in urinary bladder wall. The diagnosis and prognosis of bladder paraganglioma has not been well established. In addition, non-functioning paragangliomas of the urinary bladder have rarely been reported (1-4). Here we present a rare case of an asymptomatic patient with non-functioning paraganglioma of the urinary bladder. CASE REPORT A tumor of the urinary bladder was found during a routine physical examination of a 45-year-old man. The patient had been in a good health without abdominal and urinary tract symptoms. Routine hematological and biochemical examinations showed no evidence of hypertension. Ultrasound revealed a mass (1.4*1.1 cm) on the left wall of the bladder. Color Doppler sonography showed the mass with abundant blood supply (Figure 1 A, B). Non-contrast and contrast CT of the abdomen showed a solitary tumor protruding into the bladder (Figure 1 C, D). Metastatic disease was not found in other abdominal organs. The patient was diagnosed with synchronous nonfunctional paraganglioma in retroperitoneum and urinary bladder, and underwent a transurethral resection of bladder tumor. The mass was well circumscribed (Figure 2A), and tumor cells were arranged in a nested pattern (Figure 2B). Figure 1. Ultrasound and computed tomography images. Ultrasound revealed a mass on the left wall of the bladder (A, arrow), color Doppler sonography showed that the mass had abundant blood supply (B, arrow), Non-contrast CT (C) and contrast-enhanced CT (D) showed a solitary tumor protruding into the bladder (arrow). Urology Journal/Vol 17 No. 4/ July-August 2020/ pp. 426-428. [DOI: 10.22037/uj.v0i0.4741] Vol 17 No 04 July-August 2020 112 Histopathological examination showed positive stain- ing for NSE, Syn and CgA, and Ki-67 staining revealed a proliferation index of < 1%. On a recent follow-up after one year, ultrasound examination and cystoscopy examination showed no signs of recurrence. DISCUSSION Paraganglioma of the urinary bladder is extremely rare, accounting for less than 0.05% of all bladder neoplasm. In particular, 10-15% of such tumors are non-function- ing and the patients had no history of hypertension, headache or flushing that would suggest a diagnosis of paraganglioma(5). Thus non-functioning paraganglio- mas are more difficult to diagnose. Imaging examinations are essential for preoperative localization of paragangliomas. Ultrasound showed the tumor as a submucosal homogeneous mass with contin- uous mucosa and abundant blood supply. Scintigraphy with I-123 labelled MIBG offered superior specifici- ty than CT and MRI(6). PET has an increased accura- cy compared with MIBG scans for the localization of paragangliomas due to the higher spatial resolution of PET scanning(7). The tumors in cystoscopy appeared as globular submucosal masses protruding into the blad- der. However, the significance of diagnostic cystos- copy and biopsy is limited since it has a low positive rate, risk of bleeding and may provoke a hypertensive crisis if the tumor is functional. Therefore, histologi- cal and immunohistochemical diagnosis is important. The tumors show histological features similar to adre- nal pheochromocytomas and the cells usually grow in a characteristic nested Zellballen pattern. Chromogra- nin, synaptophysin and NSE may aid the identification of neural tissue and neuroendocrine cells. A positive staining with synaptophysin, NSE, CgA and S-100 was observed in present case, which was compatible with paraganglioma(8). Therefore, differential diagnosis of paraganglioma depends on histological and immuno- histochemical aspects. The most effective treatment of paraganglioma is sur- gery, including transurethral resection, partial or csy- tectomy and laparoscopy partial cystectomy. However, the optimal management mode is still uncertain. For patients with paroxysmal hypertension it is necessary to stabilize hypertension before the operation by using alpha-blocking drugs, similar to treatment for other pheochromocytomas(9). In this case, although the pa- tient was asymptomatic, we successfully performed a transurethral resection of the tumor to prevent its pro- gression and metastasis, and blood pressure was sta- ble during the operation. We chose conventional loop resection because the tumor was relatively small and this resection has little impact on the patient’s quality of life. In addition, this technique has very low risk of bladder perforation. Primary non-functioning bladder paraganglioma is easily misdiagnosed(10). This case is unique because of two rare synchronous nonfunctional paraganglioma in retroperitoneum and urinary bladder without any clin- ical symptoms. If CT or cystoscopy reveals a mass well-defined that is located in the submucosa with an intact surface and there is no symptom of hematuria, a diagnosis of bladder paraganglionma must be consid- ered. A definitive diagnosis may be reached by histo- logical analysis. CONFLICT OF INTEREST The authors report no conflict of interest. REFERENCES 1. Verma A, Pandey D, Akhtar A, Arsia A, Singh N. Non-function paraganglima of retroperitoneum mimicking pancreatic mass with concurrent urinary bladder paragan glioma: an extremely rare entity. J Clin Diagn Res. 2015;2:XD09-XD11. 2. Liang J, Li H, Gao L, Yin L, Yin L, Zhang J. Bladder Paraganglioma: Clinicopathology and Magnetic Resonance Imaging Study of Five Patients. Urol J. 2016;13:2605-2611. 3. 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