Asymptomatic and Biochemically Silent Pheochromocytoma with Characteristic Findings on Imaging

Perioperative Management Challenges in Silent Pheochromocytoma: A Case Report and Literature Review

Silent pheochromocytomas, frequently misdiagnosed as nonfunctioning adrenal adenomas, carry a high risk of perioperative hemodynamic instability. This case underscores the importance of thorough preoperative biochemical screening, proactive anesthetic strategies, and continuous intraoperative monitoring. Effective multidisciplinary management is crucial to prevent life-threatening complications and achieve optimal surgical outcomes.

Silent pheochromocytoma in adrenal incidentaloma: unveiling clinical and radiological characteristics

Purpose

Silent pheochromocytoma refers to tumors without signs and symptoms of catecholamine excess. This study aimed to clarify the clinical, radiological characteristics, and perioperative features of silent pheochromocytomas diagnosed after adrenalectomy for adrenal incidentaloma.

Methods

Medical records of patients who underwent adrenalectomy for adrenal incidentaloma and were subsequently diagnosed with silent pheochromocytoma between January 2000 and December 2020 were retrospectively reviewed for demographic, diagnostic, surgical, and pathological findings.

Results

Of the 130 patients who underwent adrenalectomy for incidentaloma, 8 (6.1%) were diagnosed with silent pheochromocytoma. Almost all patients had no hypertensive symptoms and their baseline hormonal levels remained within normal ranges. All patients exhibited tumor size >4 cm, precontrast Hounsfield unit >10, and absolute washout <60%. Intraoperative hypertensive events were noted in 2 patients (25.0%) in whom antiadrenergic medications were not administered. All patients in the intraoperative hypertensive event group exhibited atypical features on CT, whereas 83.3% of patients in the non-intraoperative hypertensive event group showed atypical features on CT imaging.

Conclusion

Silent pheochromocytomas share radiological traits with malignant adrenal tumors. Suspicious features on CT scans warrant surgical consideration for appropriate treatment. Administering alpha-blockers can enhance hemodynamic stability during adrenalectomy in suspected silent pheochromocytoma cases.

Biochemically Silent Pheochromocytoma in an Asymptomatic Patient With a Unilateral Lipid-Poor Adrenal Adenoma

In this case, a Caucasian woman was incidentally found to have a left adrenal gland incidentaloma a decade ago. Initial tests indicated a non-functional lipid-poor adenoma, but ongoing surveillance revealed irregularities in biochemical testing for pheochromocytoma. The patient was concurrently taking an SNRI, known to elevate biochemical markers artificially. Given the adenoma's growth and mild biochemical abnormalities, laparoscopic surgery was performed, and the tumor was found to be a 2.4 cm × 1.8 cm pheochromocytoma. Following the procedure, hormone levels normalized, and the patient experienced relief from symptoms. This case underscores the rarity of pheochromocytomas, emphasizing the importance of accurate diagnosis and effective management. Imaging techniques, notably computed tomography (CT) and magnetic resonance imaging (MRI), played a crucial role in localization, particularly through contrast-enhanced methods. Key characteristics like Hounsfield density, enhancement patterns, and washout behavior aided in distinguishing diverse adrenal masses. For cases where imaging had limitations, complementary techniques such as 23I-metaiodobenzylguanidine (MIBG) scintigraphy, specialized MR sequences, and GA-DOTATATE scans provided supplementary diagnostic insights, collectively contributing to a comprehensive clinical understanding. Despite advancements, challenges persist in differentiating specific adrenal tumors, highlighting the need for continued research and refined imaging methodologies.

Silent pheochromocytoma and paraganglioma: Systematic review and proposed definitions for standardized terminology

Pheochromocytomas and paragangliomas (PPGLs) are rare neuroendocrine tumors with heterogeneous clinical presentations and potential lethal outcomes. The diagnosis is based on clinical suspicion, biochemical testing, imaging and histopathological confirmation. Increasingly widespread use of imaging studies and surveillance of patients at risk of PPGL due to a hereditary background or a previous tumor is leading to the diagnosis of these tumors at an early stage. This has resulted in an increasing use of the term "silent" PPGL. This term and other variants are now commonly found in the literature without any clear or unified definition. Among the various terms, "clinically silent" is often used to describe the lack of signs and symptoms associated with catecholamine excess. Confusion arises when these and other terms are used to define the tumors according to their ability to synthesize and/or release catecholamines in relation to biochemical test results. In such cases the term "silent" and other variants are often inappropriately and misleadingly used. In the present analysis we provide an overview of the literature and propose standardized terminology in an attempt at harmonization to facilitate scientific communication.