6402 Unsuspected Bladder Mass Turns Out To Be A Paraganglioma

Abstract Disclosure: S. Lamichhane: None. A. Flowers: None. D.T. Price: None. A. Kaur: None. Background: Urinary bladder (UB) paragangliomas are extremely rare tumors comprising of less than 0.05% of all bladder neoplasms and 10% of all paragangliomas. The diagnosis is usually suspected based on clinical features of painless hematuria, episodic headaches, hypertension, palpitations associated with micturition or bladder and confirmed biochemically by elevated urinary and/or plasma fractionated metanephrines (MN). Here, we present a case of a UB mass that was initially diagnosed on biopsy and subsequent biochemical workup revealed elevated MN. Case Report: A 64-year-old man with type 2 diabetes and hypertension, admitted for revision surgery of subdural hematoma was incidentally found to have a 3.3 x 3.4 x 3.9 cm polypoid heterogenous hyper enhancing UB mass attached to the anterior wall on CT abdomen done for abdominal pain. Cystoscopy and TURBT were complicated by hypertensive urgency. Pathology turned out to be paraganglioma. Detailed history at this time revealed a long-standing history of frequency, urgency, nocturia 4 times nightly, recurrent urinary tract infections, an episode of gross hematuria 1-2 years ago, and difficulty controlling blood pressure on 4 anti-hypertensives. Subsequently, labs showed plasma free MN of 97 pg/ml (ref range <=57), free normetanephrine (NMN) of 2392 pg/ml (ref range <=148), and total MN of 2489 pg/ml (ref range <=205). Genetic panel was negative for SDHA, SHD, AF2, SDHB, SHDC, SDHD, VHL, RET, TMEM127. He received 6 doses of Lantreotide due to suspicion of metastasis based on abdominal, pelvic, and inguinal lymphadenopathy seen on DOTATATE scan. After preparation with alpha and beta blockers, he underwent uneventful robot-assisted cystectomy with lymph node resection that resulted in a well-differentiated paraganglioma negative for margins, lymph node involvement, and extra bladder extension. A week later, MN reduced, plasma free MN 37 pg/ml, free NMN 178 pg/ml, and total plasma MN 215 pg/ml. His BP improved, and micturition-induced palpitations resolved. Conclusion: Due to the rarity of UB paraganglioma, the diagnosis can be missed and delayed. This has a serious implication due to the risk of hypertensive crisis during the surgery and increased risk of cardiovascular complications. This case highlights the need for awareness among physicians of the clinical presentation associated with UB paraganglioma, its early recognition and management. Presentation: 6/2/2024