School of Osteopathic Medicine, Lake Erie College of Osteopathic Medicine (LECOM), 5000 Lakewood Ranch Blvd, Bradenton, FL, 34211, USA.
Department of Radiology, University of Florida College of Medicine, Jacksonville, FL, USA.
Abdom Radiol (NY). 2022 Dec;47(12):4032-4041. doi: 10.1007/s00261-022-03483-8. Epub 2022 Mar 28.
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.
膀胱嗜铬细胞瘤（PCC）是一种罕见的肿瘤，占所有膀胱肿瘤的 0.06%，占所有 PCC 的 1%。大多数 PCC 是功能性的，它们分泌儿茶酚胺，导致临床症状如阵发性高血压、头痛、心悸和出汗。然而，有些是无功能性的和无症状的，因此难以诊断。当怀疑有膀胱 PCC 时，不应进行膀胱镜检查和活检。如果在手术前没有给予预防性抗肾上腺素能阻滞剂，它们可能会引发高血压危象。诊断工作首先通过获取血液或尿液儿茶酚胺和儿茶酚胺代谢物值来做出膀胱 PCC 的初步诊断。然后使用计算机断层扫描（CT）和磁共振成像（MRI）来定位和分期肿瘤以进行手术切除。由于 MRI 具有优越的软组织分辨率，并且能够使用多参数 MRI（mpMRI）来区分膀胱壁的各层和其他膀胱肿块，因此是检测肾上腺外膀胱 PCC 并确定局部区域分期的最佳成像方式。一旦给予抗肾上腺素能药物，切除肿瘤并通过组织学确认诊断。然而，膀胱 PCC 的鉴别诊断经常被忽视，导致在没有抗肾上腺素能药物的情况下进行手术切除，增加致命性高血压危象的风险。这使得 MRI 成为手术前分期膀胱 PCC 的重要诊断工具。这篇综述讨论了 MRI 在膀胱 PCC 中的适应证，并描述了这些肿瘤在各种 MRI 序列上的表现以及何时使用它们。我们还讨论了 MRI 如何将膀胱 PCC 与其他膀胱肿瘤区分开来。
