Paraganglioma of the Urinary Bladder: A Series of 22 Cases in a Single Center.

Objective: Paraganglioma of the urinary bladder (PUB) is rare in bladder cancer, and currently, a study examining large number of cases from a single center has not been reported. This study aimed to present the clinical features, treatments, pathological characteristics, and prognosis of PUB.

Patients And Methods: From January 2006 to June 2016, 22 patients were pathologically diagnosed with PUB in our hospital. Their clinical records, operative notes, pathological reports, and follow-up records were retrospectively reviewed.

Results: The incidence of PUB in patients with bladder cancer was 0.92%. The mean age at diagnosis was 49.8 ± 14.6 years (range, 16-76 years) and the male to female ratio was 1:1. Fourteen cases (63.6%) were functional. The common indicative symptoms included hematuria (36.4%), hypertension (31.8%), micturition syncope (27.3%), headache (18.2%), and palpitation (13.6%). All neoplasms were completely resected via transurethral resection of bladder tumor (TURBT), en bloc transurethral resection with thulium-yag laser, or partial cystectomy. Most PUB samples were positive for immunohistochemical (IHC) staining markers such as chromogranin A (CgA), Synaptophysin (Syn), CD56, and S-100 protein, while negative for IHC markers such as cytokeratins (CKs) and Melan A. According to pathological reports, 72.7% of PUB cases were at stage T2, 18.2% at T3, and 9.1% at T4. Two cases (9.1%) with metastasis were malignant. Two patients (9.1%) were lost during follow-up, and the remaining 20 patients were followed up for a period of 67.8 ± 38.5 months (range, 6-130 months). Among them, 16 patients (80%) recovered after the surgery, 1 patient (5%) died of natural causes. PUB recurred in 3 patients (15%), and 1 patient among them died of PUB.

Conclusion: Despite the rarity, PUB should be suspected in patients with unexplained symptoms such as micturition syncope, hematuria, hypertension, headache, or palpitation. Surgery and adjuvant therapies are effective treatments for PUB. Compared with open surgery, laparoscopic partial cystectomy and robot-assisted laparoscopic partial cystectomy are advantageous in the treatment of PUB. Long-term follow-up is recommended for patients with PUB.