Incidental diagnosis of nonfunctional bladder paraganglioma: a case report and literature review

Nonfunctioning paraganglioma of the bladder mimicking nested variant of urothelial cancer: A case report and clinical management

INTRODUCTION AND IMPORTANCE

Non-functioning paraganglioma of the bladder is extremely rare disease. It is important to know the presence of paraganglioma of the bladder as the early and correct diagnosis affects the management and prognosis of the patient. Pathologists may misinterpret it as part of cystitis cystica/glandularis or nested variant urothelial carcinoma, or secondary bladder involvement by prostatic adenocarcinoma. This report will contribute to the existing literature and provide valuable insights into the clinical characteristics and treatment options for this rare tumor.

PRESENTATION OF CASE

35 years old female patient presented after incidental finding of bladder mass on abdominal ultrasound during routine antenatal follow up. Cystoscope showed 2 × 2 cm single solid bladder mass. Microscopic examination was suggestive of neuroendocrine tumor with paragangliom as a differential diagnosis. Imminohistochemical studies showed positive for synaptophysin, S100, GATA-3 and negative for panCK. The patient was managed with partial cystectomy.

CLINICAL DISCUSSION

Non-functioning paragnaglioma of the urinary bladder is a rare extra-adrenal pheochromocystoma. The diagnosis is usually challenging and it may mimic urothelial carcinoma. Histopathology and immunohistochemistry are almost always confirmatory.

CONCLUSION

Urinary bladder paraganglioma may mimic nested variant of the bladder tumor. High clinical suspicion is important. Confirmation is with histopathology and immunohistochemistry. Partial cystectomy is treatment of choice.

Contrast-enhanced CT in the differential diagnosis of bladder cancer and paraganglioma

PURPOSE

We sought to summarize the value of contrast-enhanced computed tomography (CECT) in the differential diagnosis of bladder paraganglioma (BPG) and bladder cancer.

METHODS

The medical records of 19 patients with BPG (13 males, 6 females) and 56 patients with bladder cancer (49 males, 7 females) between November 2007 and June 2023 were retrospectively reviewed. All patients underwent unenhanced and contrast-enhanced CT scanning.

RESULTS

Patient age (46.4 ± 11.1 years vs. 58.6 ± 16.0 years), tumor calcification (1/19 vs. 18/56), stalk (0/19 vs. 10/56), internal vessels (15/19 vs. 19/56) and the enlarged adjacent supplying artery (14/19 vs. 10/56) were significantly different between BPG and bladder cancer (P < 0.05). The CT value in the corticomedullary phase (92.4 ± 16.6 HU vs. 64.0 ± 14.5 HU) and the contrast-enhanced value in the corticomedullary phase (54.5 ± 17.4 HU vs. 28.5 ± 12.8 HU) were significantly greater in BPG patients than in bladder cancer patients (P < 0.001), with corresponding area under the curve values of 0.930 and 0.912, respectively. The optimal cutoff values were 83.2 HU and 38.5 HU, respectively. A CT value > 83.2 HU in the corticomedullary phase and a contrast-enhanced CT value > 38.5 HU in the corticomedullary phase were used to indicate BPG with sensitivities of 78.9% and 89.5%, respectively, and specificities of 94.6% and 75.0%, respectively.

CONCLUSION

The corticomedullary phase of CECT plays an important role in the preoperative differential diagnosis of BPG and bladder cancer.

Magnetic resonance imaging of bladder pheochromocytomas: a review

Bladder pheochromocytomas (PCCs) are rare tumors that account for 0.06% of all bladder tumors and makeup 1% of all PCCs. Most PCCs are functional, and they secrete catecholamines that lead to clinical symptoms such as paroxysmal hypertension, headaches, palpitations, and sweating. However, some are nonfunctional and asymptomatic and are hence difficult to diagnose. Cystoscopy and biopsy should not be performed when bladder PCCs are suspected. They may provoke a hypertensive crisis if preventative antiadrenergic blockers are not administered prior to the procedure. The diagnostic workup begins with obtaining blood or urine catecholamine and catecholamine metabolite values to make a presumptive diagnosis of bladder PCC. Computed tomography (C.T.) and magnetic resonance imaging (MRI) are then used to localize and stage the tumor for surgical resection. MRI, due to its superior soft tissue resolution and the ability to use multiparametric MRI (mpMRI) to differentiate between layers of the bladder wall and from other bladder masses, is the optimal imaging modality to detect extra-adrenal bladder PCCs and determine locoregional staging. Once antiadrenergic medications are given, the tumor is resected, and the diagnosis is confirmed histologically. However, the differential diagnosis of bladder PCC often gets overlooked, leading to surgical resection in the absence of antiadrenergic medications, increasing the chances of a fatal hypertensive crisis. This makes MRI an essential diagnostic tool for staging bladder PCCs before surgery. This review discusses the indications for MRI in bladder PCCs and describes findings from these tumors on various MRI sequences and when to use them. We also discuss how MRI can differentiate bladder PCCs from other bladder neoplasms.

An Approach to Nonurothelial Malignancies of the Urinary Bladder in Urine Cytology

Urine cytology is an economical and convenient method of triaging patients who present with urinary symptoms as well as surveying those who have previously been diagnosed with urothelial carcinoma for recurrent or persistent disease. While the vast majority of malignancies diagnosed in urine cytology are urothelial carcinomas, it is important to recognize nonurothelial elements to inform patient prognosis and raise the possibility of involvement by a urothelial carcinoma variant, nonurothelial malignancy of the bladder, or a nonbladder primary, which may alter patient management pathways. As such, becoming familiar with morphologic features of nonurothelial malignancies in urine cytology as well as their related clinical risk factors, radiologic and cystoscopic features, differential diagnostic considerations, and the utility and pitfalls of ancillary tests can facilitate optimal patient care.

Functional Bladder Paraganglioma as an Incidental Finding During Infertility Workup

Bladder paragangliomas (PGLs) are extremely rare catecholamine-producing neuroendocrine tumors. They arise more frequently in the trigone and have unpredictable depth and behavior. Most cases typically present with a well-defined set of symptoms triggered by micturition or bladder overdistension. Besides long-term follow-up, they are usually managed by either transurethral resection (TUR) or partial cystectomy (PC). However, about 25% of all documented cases do not manifest clinically, raising both diagnosis and management challenges. This report describes an unusual case of a misdiagnosed, functional PGL arising on the bladder dome, which was fortuitously detected in a 21-year-old female during a fertility workup. Owing to its hypervascular nature and submucosal location, bladder PGL was suspected on ultrasound and CT findings and successfully diagnosed before surgery through biochemical confirmation. It was managed by cystoscopy-guided laparoscopic partial cystectomy (LPC) with good oncological and urinary outcomes, as well as no compromise of her fertility potential. To our best knowledge, this is the first case to be incidentally detected on transvaginal ultrasound during evaluation for infertility. This case also stresses the importance of considering PGL in the differential diagnosis of atypical bladder tumors, as well as conservative management through simultaneous laparoscopy and cystoscopy, when approaching young patients with large functional PGL.