Presentation, Management, and Outcomes of Urinary Bladder Paraganglioma: Results From a Multicenter Study

Genetics of urinary bladder paragangliomas: a multi-center study of a Chinese cohort

PURPOSE

Pheochromocytomas and paragangliomas (PPGLs) exhibit the highest degree of heritability among all human tumors, yet the genetics of urinary bladder paragangliomas (UBPGLs) remains poorly understood. The present study aims to examine the characteristics of a cohort of Chinese patients with UBPGLs, focusing particularly on genetics.

METHODS

The study included 70 Chinese patients with UBPGLs from 15 centers in China, 240 patients with non-head and neck PGLs (non-HNPGLs) outside the urine bladder, and 16 Caucasian patients with UBPGLs. Tumor DNA samples were sequenced by next generation sequencing. All identified pathogenic variants (PVs) were confirmed by Sanger sequencing.

RESULTS

Among the 70 Chinese patients, PVs were identified in 38 cases: 23 in cluster 1 A (13 SDHB, 1 SDHD, 1 SDHA, 4 IDH1, 2 SLC25A11, and 2 FH), 4 in cluster 1B (3 EPAS1 and 1 EGLN1), and 11 in cluster 2 genes (7 HRAS, 1 FGFR1, 2 NF1, and 1 H3F3A). Compared with other non-HNPGLs, UBPGLs had more PVs in cluster 1 A genes (32.9% vs. 14.2%, p < 0.001), but fewer in cluster 1B (5.7% vs. 19.2%, p = 0.002) and cluster 2 genes (15.7% vs. 42.5%, p < 0.001). PVs in SDHB (18.6%) was the most common in Chinese patients with UBPGLs, followed by HRAS (10.0%). No PVs was found in 45.7% of all UBPGLs. PVs in HRAS, SLC25A11, EPAS1, and FH were also identified in Caucasians with UBPGLs.

CONCLUSION

Chinese patients with UBPGLs have a diverse genetic profile. PVs in cluster 1 A genes underlie nearly 1/3 of patients, highlighting the importance of genetic testing. Diverse germline and somatic PVs are also present in Caucasian patients with UBPGLs.

Clinicopathological features analysis of Paraganglioma of urinary bladder: A retrospective study

Paraganglioma of urinary bladder (PUB) is a rare neuroendocrine neoplasm. This study is a retrospective analysis of clinicopathological features in 11 cases of PUB. The studied cohort included seven male and four female patients with a median age of 64 years (range 37-73 years). The maximum tumor diameter ranged from 1 to 4 cm (median: 2.5 cm). Macroscopically, most lesions appeared as smooth, polypoid intraluminal protrusions; one case exhibited a nodular mass extending into the outer bladder wall. Microscopic evaluation demonstrated tumor infiltration into the muscularis propria (6 cases) or both lamina propria and muscularis propria (5 cases). Tumor cells were arranged in nested (Zellballen) or organoid patterns. Tumor cells uniformly expressed CD56, synaptophysin, and chromogranin. The Ki-67 proliferation index was ≤8 % in 10 cases; one case with a 4 cm tumor demonstrated a higher Ki-67 index (20 %), correlating with infiltrative growth and increased mitotic activity. Among the 10 cases that were evaluated, 2 (20 %) showed a loss of SDHB expression; Eight (80 %) of 10 cases were GATA3-positive, and all cases were negative for OCT3/4. Nine (81.8 %) underwent transurethral resection of bladder tumor, and 2 (18.2 %) underwent partial cystectomy. Intraoperative blood pressure fluctuations were observed in 2 patients (18.2 %). The median follow-up time was 26 months (range 4-73 months); one patient experienced a recurrence of endometrial cancer 4 years later and was lost to follow-up at 73 months; the remaining 10 patients survived without recurrence or metastasis. Improved preoperative recognition of PUBs relies on integrating clinical, biochemical, and imaging findings. Standardized immunohistochemical panels may enhance diagnostic accuracy.

Metastatic Malignant Paraganglioma of Rare Sites Failed on Conventional Treatments Demonstrating Beneficial Response to 177 Lu-DOTATATE PRRT

The incidence of paraganglioma (PGL) is rising due to better imaging modalities employed for evaluating incidentaloma and surveillance of the asymptomatic carriers. Benign and malignant PGLs often cannot be reliably diagnosed on histology alone, and the documentation of metastases is important in the diagnosis of malignancy. Advancement in genomics has improved our understanding of PGL. 68 Ga-DOTATATE positron emission tomography (PET)/computed tomography (CT) scan shows a significant superior detection rate compared with other conventional functional and anatomical imaging modalities, can detect rare sites of primary disease in PGL, and also aids in patient selection for peptide receptor radionuclide therapy (PRRT). PRRT is increasingly used in metastatic setting with good symptomatic and biochemical response and disease stabilization in metastatic PGL patients. We present a series of three patients with PGLs located in rare primary sites (sigmoid colon, urinary bladder, and carotid body space), which showed recurrence of disease on conventional treatments and developed metastatic disease in the lymph nodes, liver, skeleton, and lungs. PRRT with 177 Lu-DOTATATE achieved symptom control, favorable biochemical and imaging responses, and increased progression-free and overall survival rate in the described patients.

Temozolomide as neoadjuvant therapy for bladder paraganglioma

Bladder Paraganglioma (BPG) is a rare form of pheochromocytoma and paraganglioma (PPGL) characterized by elevated blood pressure when urinating, headache, dizziness, palpitations, and hematuria. Surgical resection is the most commonly used treatment for BPG. Here, we reporte a man who initially presented with hypogastralgia and hematuria and was diagnosed as BPG at local hospital. The size of mass was too huge to receive partial cystectomy at diagnosis. Then this patient was referred to our medical center. After evaluation, we chose temozolomide as neoadjuvant therapy to reduce the tumor size. Followed by seven cycles of temozolomide, the tumor was decreased and was successfully removed via partial cystectomy.

A rare case of bladder paraganglioma treated successfully with robotic partial cystectomy

Bladder paragangliomas are rare extra-adrenal urological tumors that account for around 0.05% of bladder cancers. Their diagnosis is often delayed because of the rarity of these tumors. There is a risk of an intraoperative hypertensive crisis if not diagnosed or identified before surgical removal. We describe a case of a 36-year-old lady presented with a 10-year history of post-micturition palpitations and headaches. Her biochemical workup showed raised urinary normetanephrine levels and imaging showed a 123I MIBG-avid bladder mass compatible with bladder paraganglioma, although interestingly almost no tracer was picked up in 68Ga DOTATATE imaging. She was started on phenoxybenzamine to control her blood pressure prior to surgery. She underwent a successful robotic partial cystectomy with no complications. After surgery, she remained symptom-free. Bladder paragangliomas are rare neuroendocrine tumors of the bladder, which need to be diagnosed and managed effectively to avoid intraoperative and long-term complications.

Learning points

It is important for patients with a bladder lesion to have a comprehensive differential assessment and biochemical and radiological investigations including functional imaging.Multiple imaging modalities along with what is available are useful in the assessment of bladder paraganglioma.The key role of the multidisciplinary team is to plan treatment in the perioperative period for minimizing risk, especially in situations where optimal management is actively debated.

Recent discoveries of Sino-Caucasian differences in the genetics of phaeochromocytomas and paragangliomas

Pheochromocytomas and paragangliomas (PPGLs) represent the highest degree of heritability of any known tumor types in humans. Previous studies have characterized a dramatic difference between Chinese and European Caucasians with regards to both genetics and clinical features of PPGLs. The proportion of PGLs in Chinese patients was higher than in Caucasians, and the prevalence of metastasis was much lower in Chinese patients. Compared with Caucasians, there were more pathogenic variants (PVs) found in HRAS and FGFR1, but less in NF1 and SDHB. There were less germline PVs found in Chinese patients. Importantly, in Chinese patients, there was a large proportion of PGLs with PVs found in HRAS and FGFR1, mostly with epinephrine-producing capacity. This finding provided solid evidence that genetics (cluster 1 vs. 2), rather than location (PCC vs. PGL), determines the catecholamine-producing phenotype. Besides, the lower prevalence of SDHB partially explained lower occurrence of metastatic lesions in Chinese patients. These findings underscore the importance of considering ethnic differences when evaluating PPGLs and patient outcomes.

Non-functional muscle-invasive bladder paraganglioma-a case report

Background

Extra-adrenal pheochromocytoma (paraganglioma) of the urinary bladder is a rare tumor, accounting for 0.05% of bladder tumors and less than 1% of all paragangliomas. In the genitourinary tract, paragangliomas are most commonly found in the bladder. These tumors have aggressive malignant potential, so complete surgical resection for localized disease is important. Paragangliomas may be non-functional or functional with catecholamine secretions. Although these tumors are rare and difficult to distinguish from urothelial carcinoma (UC), intraoperative manipulation of these tumors may lead to a catecholamine surge and intraoperative complications. Preoperative or early intraoperative recognition of this tumor would facilitate appropriate alpha blockade to minimize morbidity.

Case Description

Herein we report a rare non-functional paraganglioma arising from the bladder of a 46-year-old male. This case is notable for the location of the mass, requiring a 70-degree cystoscopic lens for complete visualization near the bladder neck, and for the identification of a golden-yellow sessile mass during the resection. Upon visualization of this mass, the operation should be paused for close hemodynamic monitoring and assess for signs of hypertensive crisis prior to continuing without alpha blockade.

Conclusions

Suspected localized bladder paraganglioma cases should be optimized hemodynamically and managed surgically. Visualization of a sessile bladder mass on gross examination with golden-yellow tumor during the resection should prompt suspicion for a paraganglioma. Biochemical evaluation with serum or urine catecholamines, metanephrines, and normetanephrines should be performed to assess for tumor functionality.

Diagnosis and management of urinary bladder paragangliomas: A Sino-American-European retrospective observational study

OBJECTIVE

Paragangliomas of the urinary bladder (UBPGLs) are rare neuroendocrine tumours and pose a diagnostic and surgical challenge. It remains unclear what factors contribute to a timely presurgical diagnosis. The purpose of this study is to identify factors contributing to missing the diagnosis of UBPGLs before surgery.

DESIGN, PATIENTS AND MEASUREMENTS

A total of 73 patients from 11 centres in China, and 51 patients from 6 centres in Europe and 1 center in the United States were included. Clinical, surgical and genetic data were collected and compared in patients diagnosed before versus after surgery. Logistic regression analysis was used to identify clinical factors associated with initiation of presurgical biochemical testing.

RESULTS

Among all patients, only 47.6% were diagnosed before surgery. These patients were younger (34.0 vs. 54.0 years, p < .001), had larger tumours (2.9 vs. 1.8 cm, p < .001), and more had a SDHB pathogenic variant (54.7% vs. 11.9%, p < .001) than those diagnosed after surgery. Patients with presurgical diagnosis presented with more micturition spells (39.7% vs. 15.9%, p = .003), hypertension (50.0% vs. 31.7%, p = .041) and catecholamine-related symptoms (37.9% vs. 17.5%, p = .012). Multivariable logistic analysis revealed that presence of younger age (<35 years, odds ratio [OR] = 6.47, p = .013), micturition spells (OR = 6.79, p = .007), hypertension (OR = 3.98, p = .011), and sweating (OR = 41.72, p = .013) increased the probability of initiating presurgical biochemical testing.

CONCLUSIONS

Most patients with UBPGL are diagnosed after surgery. Young age, hypertension, micturition spells and sweating are clues in assisting to initiate early biochemical testing and thus may establish a timely presurgical diagnosis.

Case report: A novel somatic SDHB variant in a patient with bladder paraganglioma

Background

Paragangliomas (PGL) are rare neuroendocrine tumors derived from the autonomic nervous system paraganglia. Urinary bladder paragangliomas (UBPGL) originate from the sympathetic neurons of the urinary bladder wall and represent 0.7% of all paragangliomas and <0.05% of all bladder tumors. PGL and UBPGL can be associated with SDHB, SDHD, NF1, and VHL gene variants, with the most common germline alterations found in SDHB and VHL.

Case report

We report a case of a 42-year-old woman who presented with menorrhagia/hematuria, uterine leiomyomas, as well as cardiac and bladder masses. The cardiac mass was favored to be a myxoma based on clinical findings, while the bladder mass was diagnosed as UBPGL. A novel SDHB mutation (c.642G>A, p Q214Q), detected in the UBPGL, was proven to be somatic. Although this variant was seemingly synonymous, it was predicted to have a loss of function due to the splice site effect, which was further supported by the immunohistochemical loss of SDHB.

Conclusion

This case highlights the challenges of diagnosing an extremely rare entity, bladder paraganglioma, with an emphasis on the multidisciplinary approach to navigate various clinical and imaging findings that may initially be misleading. In addition, a novel loss of function SDHB variant that could have been overlooked as a synonymous variant is herein reported, while also illustrating the importance of both germline and somatic mutation testing.

Unrecognised paraganglioma of the urinary bladder precipitating hypertensive crisis

Bladder paragangliomas (bPGLs) account for only 0.06% of all bladder tumours, most commonly presenting with post-micturition syncope and hypertensive crisis. Silent paragangliomas are very rare, and failure to recognise them in the perioperative setting can precipitate a hypertensive crisis in the absence of sufficient alpha-blockade. Here, we describe a case of unrecognised bPGL in a woman with pre-existing hypertension and a single prior episode of haematuria thought to be related to urothelial carcinoma. She was found to have a low-grade non-invasive papillary urothelial carcinoma (potentially the cause of her haematuria) and an unrelated vascular-appearing tumour causing hypertensive crisis and broad complex tachycardia on resection. This was confirmed to be a bPGL on histology for which she underwent definitive management with a partial cystectomy following blood pressure management.

Metastatic paraganglioma presenting with spinal cord compression requiring urgent surgery

We report a rare case of a functional bladder paraganglioma diagnosed in a young man who presented with acute compressive thoracic myelopathy secondary to vertebral metastasis. A histological diagnosis of a metastatic paraganglioma was made following biopsy of a rib lesion. CT revealed a lesion in the inferior wall of the bladder, which demonstrated avid uptake on 68Ga-DOTATATE PET/CT. Serum metanephrine levels were more than 40 times the upper limit of normal. The patient was hypertensive and treatment with doxazosin was initiated. In view of neurological deterioration, he required urgent spinal decompression to preserve neurological function and prevent permanent paraplegia. Despite inadequate alpha-blockade, surgery was successful, and the perioperative course was uneventful. Alpha-blockade was subsequently optimised. Treatment with cyclophosphamide, vincristine and dacarbazine was started but, in view of disease progression, treatment was subsequently changed to sunitinib.

Case Report: Octreotide plus CVD chemotherapy for the treatment of multiple metastatic paragangliomas after double resection for functional bladder paraganglioma and urothelial papilloma

Background

Metastatic pheochromocytomas and paragangliomas are rare neuroendocrine tumors with a poor prognosis. Bladder paraganglioma concomitant with urothelial papilloma is even rarer. However, the rate of tumor response to cyclophosphamide-vincristine-dacarbazine (CVD) chemotherapy and 5-year overall survival for patients with metastatic PPGLs remained lower. We described, for the first time, a case of a patient with multiple metastatic bladder PGL who received octreotide LAR combined with CVD chemotherapy after urological surgery and then octreotide therapy was continued during follow-up.

Case presentation

A 43-year-old male patient was admitted to the urology department for frequent micturition syncope concomitant with malignant hypertension. Preoperative findings were elevated levels of normetanephrine in 24-h urine or plasma. CT and MRI indicated diagnosis of suspicious bladder paraganglioma. Transurethral resection of bladder tumor combined with laparoscopic partial cystectomy was performed successfully after preoperative phenoxybenzamine with aggressive volume repletion for 7 days. The result of postoperative pathology was immediate-risk functional bladder paraganglioma (T2N0M0, Stage II) concomitant with urothelial papilloma, and the immunohistochemistry results of PPGL were positive for Ki-67 (15%), SDHB, CgA, and SSTR2. The patient achieved enhanced recovery with normal urination and no syncope after surgery. However, the results of ¹⁸F-FDG and ¹⁸F-DOTATATE PET/CT found that the metastatic localizations of bladder PGLs were in the liver, lung, and bones at the 8th month after surgery. The patient received octreotide long-acting repeatable plus six courses of CVD chemotherapy for 6 months, and then octreotide therapy was continued every 3 months until now. Metastatic localizations were stable in CT scans, and vanillylmandelic acid in 24-h urine was maintained at lower levels during follow-up.

Conclusion

Octreotide long-acting repeatable plus CVD chemotherapy after surgery could achieve stable disease in the case with multiple metastatic bladder PGLs, and the following octreotide therapy could maintain a state of stable disease during the period of 6-month follow-up.

Bladder Paraganglioma Associated With Succinate Dehydrogenase A Mutation Presenting as Pelvic Pain

A 21-year-old female presented to the hospital with acute onset left pelvic pain that began while urinating. Ultrasound of the pelvis revealed a 1.7 cm structure within the bladder wall. Follow-up imaging with magnetic resonance imaging confirmed a 1.9 cm mass in the urinary bladder wall. Cystoscopy with transurethral resection was performed. Histopathology of the obtained tissue confirmed the diagnosis of paraganglioma. Laboratory evaluation revealed evidence of catecholamine excess with elevated urine norepinephrine, urine normetanephrine, and plasma free normetanephrine. Functional imaging with Ga-DOTATATE positron emission tomography-computed tomography (PET-CT) revealed increased uptake in the region of the known mass without findings of metastasis. Genetic testing revealed succinate dehydrogenase A mutation, consistent with paraganglioma syndrome 5. The patient was treated with alpha-adrenergic blockade prior to partial cystectomy. Urinary bladder paraganglioma is a rare entity. The diagnosis requires a high index of clinical suspicion due to variable presentation. Hypertension and other signs of catecholamine excess, especially in relation to micturition, are important clues. Despite evidence of catecholamine excess in most patients with bladder paraganglioma, the majority are diagnosed after biopsy, indicating a need for improved diagnostic strategies in this patient population. Early diagnosis and treatment are essential to prevent potentially lethal cardiac complications and tumor metastasis.