S. Purnell1, A. Sidana1, M. Maruf1, C. Grant2, S. Brancato1, P. Agarwal1 1National Cancer Institute,Urologic Oncolocy Branch,Bethesda, MD, USA 2George Washington University Hospital,Urology,Washington, DC, USA
Introduction: Extra-adrenal paragangliomas (PGL) are infrequent, benign, neuroendocrine tumors arising from chromaffin cells of the autonomic nervous system. While most develop above the umbilicus, they have been reported in the genitourinary (GU) tract. Due to the paucity of literature on the rates of GU paraganglioma, our study aims to describe demographic, pathologic, and clinical characteristics of GU PGL, and compare them to non-GU sites of PGL.
Methods: Data was collected from the SEER 18 Database to compare GU and non-GU PGL diagnosed between 2000 and 2012. Chi-square and unpaired t-tests were used. Kaplan-Meier analysis and a log rank test were used to determine overall survival and statistical significance, defined as p<0.05.
Results:299 cases of PGL were retrieved and only 20 (6.7%) arose from the GU tract. 83.3% GU PGLs developed in the bladder, subsequently the kidneys/renal pelvis (16.7%), and spermatic cord (2%). Non-GU PGL developed most frequently within the endocrine system (43%). Overall, PGL was more common in men than women. The mean age at diagnosis in years was higher in non-GU than GU PGL (50.4±17.2 vs 40.8±15.6, p=0.026). GU PGL was less common in whites compared to PGL at other sites (p=0.033). The majority (50%) of GU PGL was organ confined while 5.7% of non-GU PGL was localized at diagnosis. All cases of PGL were treated with surgery. 30% of patients with GU PGL underwent LN dissection and none had radiation. There were 2 (10%) cause-specific deaths in the GU PGL groups between 2000 and 2012. 5-year overall survival was 93.3% for GU PGL versus 65.5% in non-GU PGL (p=0.062).
Conclusion:Genitourinary PGL remains rare, with low incidence (6.7% of all PGL cases) in the US population between 2000 and 2012. Also, it had high 5-year overall survival compared to PGL developing outside of the GU tract. The bladder represents the most common site of involvement and surgery is the mainstay of treatment for GU PGL. Clearer prognostic factors are needed to better elucidate PGL management in the future thus pooled studies from various institutions with detailed clinical information are needed to delineate these prognostic factors.