Functional paragangliomas of the urinary bladder: a report of 9 cases.

BACKGROUND AND OBJECTIVE: Functional paraganglioma of the urinary bladder (FPUB) is a rare tumor. Misdiagnosis of FPUB before operation can lead to serious intraoperative consequences. In this article, we reported our experience in preoperative diagnosis and surgical treatment of FPUB.

METHODS: Clinical data of nine patients with FPUB treated between June 1985 and January 2009 at Peking Union Medical College Hospital were analyzed.

RESULTS: All patients underwent urinary catecholamine (CA) detection, B-ultrasound, CT and/or MRI scan; 5 underwent nailfola microcirculation inspection; 4 underwent 131I-metaiodobenzyl guanidine (MIBG) detection; and 6 underwent 111In-DTPA-Octreotide (OCT) scintiscan. According to the UICC bladder tumor classification, 5 patients had T2, 3 had T3, and 1 had T4 disease. All patients underwent surgical treatment, and 1 received 131I-MIBG therapy. All patients had paroxysmal hypertension and palpitation and six had cold sweat, headache, and dizziness after emphatic urination. The definitive diagnosis was made by histopathologic examination of the removed tumors and was confirmed in 7 cases by the immunohistochemical staining of chromogranin A, Ki-67 and S100 protein. The tumor consisted of discrete aggregates of zellballen cells separated by a network of vascular channels. One patient had metastases in the pelvic lymph nodes, liver and colon. Follow-up ranged from 7 to 289 months (mean, 127.2 ± 34.2). Six of the nine cases reported here were found in the usual locations. One patient had multiple tumors. The catecholamine level was elevated under basal conditions in 8 patients and during endoscopic resection of the tumor in 1 patient; it returned to normal after surgery in 8 patients. Three patients had recurrence and 1 had metastasis following surgery.

CONCLUSIONS: Early preoperative diagnosis of FPUB is difficult, but it should be suspected in patients with typical tetrad symptoms: headache and micturition syncope, sweating, palpitation and hematuria. In those patients with unresectable multiple tumors, medicine and 131I-MIBG therapy may be helpful for controlling hypertension and delaying disease progression. Advanced classification (≥T3), multifocal tumors and CgA expression are risk factors of recurrence and metastasis.