Urinary bladder paraganglioma (UBP) is a rare neuroendocrine neoplasm. It accounts for less than 1% of urinary bladder tumors and less than 6% among all types of paragangliomas. More commonly, UBP occurs in the female population aged 20-40 years old. UBP is classified into functional and non-functional types, and the majority is functional, leading to symptoms and signs of excess catecholamine, including hypertension, palpitation, syncope, and headache. Non-functional UBP comprises about 15% of UBPs and lacks the excess secretion of catecholamine, which often leads to misdiagnosis as urothelial cancer due to its rarity and nonspecific symptoms - increased urinary frequency/urgency and painless gross hematuria. Here, we present a rare case of a non-functional UBP.
A 65-year-old male with BPH presented to ER with a 6-month history of urinary retention. He also was experiencing intermittent hematuria and dysuria during this time but otherwise remained asymptomatic without headache, dyspnea, wheezing, or diarrhea. Physical exam showed normal BP and no suprapubic tenderness on palpation. UA showed gross hematuria. Subsequent cystoscopy showed thickening of the bladder dome and an 8 mm lesion. Transurethral resection of bladder tumor (TURBT) was performed, and pathology showed 1 cm tumor confined to submucosa with questionable margins. Chromogranin, synaptophysin, CD56, GATA3, CD10 were stained positive; cytokeratin AE1/AE3, cytokeratin 34betaE12, SOX10, S100, and calretinin were negative. From morphology and immunochemistry, the diagnosis of UBP was made. Free metanephrine, plasma normetanephrine, 24-hour urine metanephrine and normetanephrine levels were not elevated. Post-TURBT MRI abdomen showed no other suspicious lesions. A wide re-resection of the bladder dome was performed due to the questionable margins from the initial surgery, and pathology showed benign bladder tissue with unremarkable immunostains, indicating no overt features of residual paraganglioma.
Due to its paucity and uncertain biological behavior, the prognosis of UBP is not well established. While most UBP are benign, 10-15% of cases are malignant. High expression of VEGF and or abnormal vessel architecture in the tumor cells raise suspicion of malignancy. However, typically, definitive evidence of malignancy in paraganglioma is its invasion of adjacent organs or distant metastasis. The local recurrence rate ranges from 5-15%, thus necessitating long-term surveillance for 10-years. Systemic chemotherapy, including cyclophosphamide, vincristine, dacarbazine (CVD), or temozolomide, is necessary for distant metastatic or symptomatic disease. Iobenguane I-131 or Lutathera can be utilized with positive MIBG or 68Ga DOTATATE scan, respectively. Otherwise, surgical extirpation remains the choice of curative intent, and a multidisciplinary approach consisting of urologists, medical/radiation oncologists, and endocrinologists would be warranted for this rare entity of disease.
| Identifer | oai:union.ndltd.org:ETSU/oai:dc.etsu.edu:asrf-1879 |
| Date | 07 April 2022 |
| Creators | Kim, Do Young, M.D, Khan, Ali, M.D, Singal, Sakshi, M.D, Jaishankar, Devapiran, M.D |
| Publisher | Digital Commons @ East Tennessee State University |
| Source Sets | East Tennessee State University |
| Detected Language | English |
| Type | text |
| Source | Appalachian Student Research Forum & Jay S. Boland Undergraduate Research Symposium |
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