Treatment responses to antiangiogenetic therapy and chemotherapy in nonsecreting paraganglioma (PGL4) of urinary bladder with SDHB mutation: A case report

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.

PGL4 syndrome in a patient with synchronous paraganglioma-pheochromocytoma

Pheochromocytoma and paraganglioma (PGL) are rare neuroendocrine tumours, frequently associated with genetic syndromes. We report the case of a man in his 40s with a left anterior neck mass and a history of hypertensive crisis, heavy sweating and constipation. Biochemical tests showed increased plasma and urine normetanephrines. Neck ultrasound suggested left carotid body PGL, but it was mandatory to search for other lesions. Whole-body MIBG failed to show abnormal uptake. Abdominal MRI was suggestive of another PGL, anterior to the right adrenal gland. Abdominal surgery was performed uneventfully under alpha and beta blockers. This intervention proved to be effective, as normetanephrines levels became completely normal after 1 month. Carotid body PGL was successfully excised 4-months later. Genetic study identified a large deletion in exon 1 of the SDHB gene allowing the diagnosis of paraganglioma syndrome type 4 (PGL4). After 19 months of follow-up, he is still on clinical and biochemical remission and will continue life-long surveillance.

Bladder Paraganglioma: Three Cases Report and Literature Review

BACKGROUND

Bladder paraganglioma (BPG) is one of the rare neuroendocrine neoplasms that develops from neural crest cells. It categorizes into functional and non-functional types based on the catecholamines secretion. Currently, functional BPG is predicted in advance based on signs and symptoms of catecholamine excess, such as hypertension and "micturition attacks". However, it is often overlooked because of its rareness. Misdiagnosis of a functional tumor may increase the risk of surgical intervention.

CASE PRESENTATION

We reported 3 cases of BPG that they were admitted to the hospital due to abdominal pain or gross hematuria. Computed tomography (CT) scans showed space-occupying lesions in the bladders with diameters less than 3cm. There were no typical catecholamine excess symptoms before surgical intervention. Postoperative pathology confirmed BPG after removal of the tumor. We also analyze 69 cases of BPG that has been reported and found that 78.0% cases were functional among the tumors larger than 3cm.

CONCLUSION

Bladder tumors larger than 3cm in diameter can serve as an additional predictor of functional BPG. Patients who are suspected should undergo magnetic resonance imaging (MRI) scans, 123/131 metaiodobenzylguanidine (MIBG) scan, and have their catecholamine levels tested. Once the diagnosis is confirmed, patients should be started on fluid replacement therapy and adrenergic blockade to abate the disorders associated with catecholamine excess.

Sunitinib Treatment for Advanced Paraganglioma: Case Report of a Novel SDHD Gene Mutation Variant and Systematic Review of the Literature

Background

Paragangliomas (PGLs) are neuroendocrine neoplasms arising from chromaffin cells of sympathetic or parasympathetic paraganglia. Systemic therapies have been used only in metastatic PGLs. Antiangiogenic agents, such as sunitinib, could be a viable therapeutic choice in the subgroup of patients with SDH-positive PGLs. We describe the case of a man with Familial Paraganglioma Syndrome type 1 (FPGL) related to a novel mutation in SDHD gene treated with sunitinib. Furthermore, we performed a systematic review of the literature aimed to address the following question: is sunitinib treatment effective in patients with advanced/progressive/metastatic PGL?

Methods

We performed a data search using MEDLINE, Cochrane Library, and Scopus between April 2019 and September 2020. We included studies reporting data on clinical or biological characteristics, or clinical outcomes of patients with PGLs treated with sunitinib.

Results

The search leaded to the selection of 25 publications. Data from case reports and case series showed that disease control rate (DCR = stable disease + partial response + complete response) was achieved in 34.7% of cases under sunitinib treatment. In 39% of patients DCR was followed by progressive disease (PD) or tumor relapse, 26.1% patients showed PD. Data from clinical trials showed that DCR was 83%, and the median progression free survival was 13.4 months.

Discussion

Data from the present literature review suggested that sunitinib could be a viable therapeutic option in advanced/progressive/metastatic inoperable PGLs. However, further trials on the efficacy of sunitinib in FPGL and sporadic PGL are needed.