Pheochromocytoma and functional paraganglioma

The Radiological Assessment of Carotid Space Lesions: A Case Series

Carotid space lesions present diagnostic challenges due to their diverse etiology and varied clinical manifestations. This article critically reviews the anatomy of the carotid space and highlights the spectrum of pathologies within this complex region, illustrated by three case studies. The cases were examined with ultrasonography (USG), computed tomography (CT), and magnetic resonance imaging (MRI). Schwannomas appeared heterogeneously hypodense on plain CT and partially hyperdense on contrast-enhanced CT (CECT), with displacement of adjacent vessels. Vagal-origin schwannomas caused the anteromedial displacement of the internal carotid artery. Paragangliomas were typically homogeneously hyperdense on CECT, with lateral displacement of the internal carotid artery when of carotid body origin. The management of carotid space lesions depends on the resectability of the tumors; unresectable tumors are managed with chemotherapy. This overview enhances clinical understanding and diagnostic accuracy, facilitating improved patient outcomes in managing carotid space lesions.

Sudden Death Due to Neck Paraganglioma: A Pediatric Case Report and Review of the Literature

Neck paragangliomas are relatively rare neuroendocrine nonsecretory tumors. They are mainly observed among adults and are often asymptomatic, causing a frequent delay in diagnosis. In pediatric cases, neck paragangliomas can be associated with adrenergic symptoms that may lead to complications.A report of a sudden death due to a carotid paraganglioma in a young girl is reported. Autopsy revealed a thoracic arotic dissection and a 4-cm jugulocarotidian mass in the absence of traumatic injuries. Histology showed no evidence of underlying aortic disease, including signs of Marfan syndrome, and a paraganglioma. Postmortem biochemistry analysis showed blood metanephrines levels 100 times higher than normal range. The cause of death was an aortic dissection complicating a neck paraganglioma. The manner of death was concluded as natural.Our case highlighted the importance for forensic pathologist to consider the diagnosis of paraganglioma in case of sudden hypertensive complications, especially among young people.

Pathology of the carotid space

The complex anatomy of the carotid space within a small confined area is unique to the head and neck and allows for a vast array of pathology. This paper will review the anatomy of the carotid space from the skull base to the thorax, defining its borders at multiple levels, as well as its contents. The paper will also describe the myriad of mass lesions and vascular pathologies that may occur within the carotid space. The discussion will include anatomic considerations in differential diagnoses, imaging features, and lesion characteristics across multiple imaging modalities including CT, MRI, ultrasound, and conventional angiography. Entities discussed include paragangliomas, nerve sheath tumors, meningioma, fibromuscular dysplasia, carotidynia, thrombus, dissection, pseudoaneurysm, and pathology of the deep cervical chain lymph nodes. Understanding the complex and unique anatomy of the carotid space, as well as the nuances of navigating a broad differential, will empower the reader to make an accurate diagnosis.

Neuroendocrine tumors: beyond the abdomen

Several classification systems for neuroendocrine tumors (NETs) exist, which use variable terminology and criteria for grading and staging. This variability in terminology can cause confusion and difficulty in recognizing which tumors are, in fact, members of this heterogeneous group of malignancies. The largest group of NETs, the gastroenteropancreatic NETs, has been well described and characterized; however, there are less-recognized extra-abdominal NETs that can arise from nearly any organ in the body. In this article, the clinical features and imaging appearances of the extra-abdominal NETs will be reviewed, compared, and contrasted. This diverse group consists of paragangliomas, Merkel cell carcinomas, esthesioneuroblastomas, NETs of the lung, and medullary thyroid carcinomas. Recognition of these tumors as part of the larger group of NETs is important for understanding how best to approach imaging for their diagnosis, staging, and potential treatment. Familiarity with the computed tomographic and magnetic resonance imaging appearances and the role of radionuclide imaging of these heterogeneous groups aids in the correct diagnosis and in treatment planning.

Implication of tumor stem-like cells in the tumorigenesis of sporadic paraganglioma

It is commonly believed that paragangliomas are rare tumors arising from the neural crest-derived chromaffin cells. Although it has been speculated that paraganglioma is related to stem cell origin, there has been lack of direct evidence demonstrating the presence of (neural) stem cells in these tumor tissues. In this study, we found a subgroup of human paraganglioma from ten clinical samples displayed definitive markers of CD133 and/or nestin, the fundamental features of neural stem cell capable of self-renewal and differentiation. A panel of lineage-specific markers was also manifest in some of these tumors, consistent with the hierarchical and heterogeneous nature of these tumors. These observations strongly suggest that at least some forms of paraganglioma maintain tumor stem-like cells (TSCs) that potentially contribute to the histologic complexity of human paraganglioma. Finally, we found that the genomic DNA structure becomes highly unstable in tumor cells of paraganglioma, indicating the loss of tight control of genomic surveillance system be an important transitory event from normal multi-potent tissue stem cells to TSCs.

Pheochromocytoma: diagnostic and therapeutic update

Pheochromocytomas are catecholamine-secreting tumors that arise from chromaffin cells of the sympathetic nervous system. In 80-85% of cases, these tumors are located in the adrenal medulla while the remainder is located in extra-adrenal chromaffin tissues (paragangliomas). Pheochromocytomas account for 6.5% of incidentally discovered adrenal tumors. These tumors may be sporadic or the result of several genetic diseases: multiple endocrine neoplasia type 2, von Hippel-Lindau syndrome, neurofibromatosis type 1, and familial paraganglioma associated with mutations in succinate dehydrogenase subunits. Diagnosis of pheochromocytoma should first be established biochemically by measuring plasma free metanephrines and urinary fractionated metanephrines. The radiological imaging tests of choice are computed tomography (CT) or magnetic resonance imaging (MRI). The first-line specific functional imaging test is scintigraphy with (123)I-metaiodobenzylguanidine (MIBG); if this test is unavailable, scintigraphy with (131)I-MIBG is the second choice. Positron emission tomography (PET) with (18)F-F-fluorodopamine (F-DA) is useful in metastatic disease. The treatment of choice is laparoscopic surgery after adequate alpha adrenergic blockade. Approximately 10% of tumors are malignant. Chemotherapy is used for inoperable disease. Prognosis is good except in malignant disease, in which 5-year survival is less than 50%. The identification of the genes causing hereditary pheochromocytoma has led to changes in the recommendation for genetic testing.

Sphenoid sinus paraganglioma: first reported case

Paragangliomas are uncommon tumors that present in the head and neck. Rarely, this benign tumor may occur in the nose and paranasal sinus. We report a case of paraganglioma involving the sphenoid sinus, discuss histologic characteristics, and review this tumor.

Feocromocitoma: uma causa rara de hipertensão arterial na infância

OBJETIVO: Relatar o caso de um adolescente com feocromocitoma, uma causa rara de hipertensão arterial na infância. DESCRIÇÃO: Adolescente internado em unidade de terapia intensiva infantil em decorrência de emergência hipertensiva, conseqüente à presença de feocromocitoma em adrenal esquerda, diagnosticado por meio de tomografia computadorizada do abdome e pela dosagem de adrenalina e noradrenalina urinárias. O paciente foi submetido à adrenalectomia esquerda, após o uso de alfa-bloqueador para controle do quadro hipertensivo. O anatomopatológico confirmou o diagnóstico do tumor. No pós-operatório, o paciente permaneceu estável, possibilitando a suspensão dos anti-hipertensivos. COMENTÁRIOS: Os feocromocitomas são tumores capazes de produzir catecolaminas, especialmente adrenalina e/ou noradrenalina. Cerca de 85 a 95% dos tumores são únicos, benignos e encontrados na medula adrenal. O feocromocitoma é um tumor de incidência rara e apenas 10 a 20% ocorrem na infância, representando uma causa rara de hipertensão arterial. Esta última é um sinal freqüente na maioria das crianças (80%), podendo ser acompanhada por cefaléia e sudorese. A encefalopatia hipertensiva consiste em uma forma de apresentação excepcional da doença. O diagnóstico pode ser realizado, na maioria dos casos, pela tomografia de abdome e pela dosagem das catecolaminas e seus metabólitos produzidos pelo tumor. O tratamento de escolha consiste na ressecção completa do tumor após o preparo farmacológico do paciente com o uso de alfa-bloqueador. No pós-operatório, a maioria dos pacientes evolui com controle do quadro de hipertensão arterial.

Extraadrenal paragangliomas of the body: imaging features

OBJECTIVE

This article illustrates the anatomic distribution of the healthy paraganglion system and the imaging and pathologic features of various extraadrenal paragangliomas occurring in the head and neck, chest, and abdomen.

CONCLUSION

Although paragangliomas can occur in a variety of anatomic locations, the majority are seen in relatively predictable regions of the body. Extraadrenal paragangliomas have nearly identical imaging features, including a homogeneous or heterogeneous hyperenhancing soft-tissue mass at CT, multiple areas of signal void interspersed with hyperintense foci (salt-and-pepper appearance) within tumor mass at MRI, and an intense tumor blush with enlarged feeding arteries at angiography.

Management of Type A Aortic Dissection and a Large Pheochromocytoma: A Surgical Dilemma

The concomitant presence of an undiagnosed pheochromocytoma at the time of an acute type A aortic dissection creates a difficult management dilemma. The case of a patient with an acute type A aortic dissection and pheochromocytoma was stabilized with catecholamine blockade before undergoing ascending aortic and total arch replacement. Fourteen days later the patient underwent resection of the pheochromocytoma. Temporizing medical stabilization of the pheochromocytoma with catecholamine blockade for a period of 5 days allowed for safe aortic reconstruction and seems to be prudent, provided that the aortic dissection remains relatively stable.

Paraganglioma presenting as a vascular malformation: case report

Paragangliomas are rare tumours that arise from extra-adrenal chromaffin cells or neuroectodermal chemoreceptor. They are high vascularised and can be functional, secreting catecholamines and other peptides. They occur anywhere from the skull base to the pelvic floor, within the paraganglion system. We present a case of paraganglioma with unusual location, atypical presentation and interesting vascular anatomy.

New functional imaging modalities for chromaffin tumors, neuroblastomas and ganglioneuromas

Nuclear medicine modalities use radiolabeled ligands that either follow metabolic pathways or act on cellular receptors. Thus, they permit functional imaging of physiological processes and help to localize sites such as tumors that harbor pathological events. The application of positron emission tomography (PET) ligands to the specific pathways of synthesis, metabolism and inactivation of catecholamines found in chromaffin tumors, neuroblastomas and ganglioneuromas can be used to provide a more thorough localization of these types of tumor. Recent advances have been made in functional imaging to localize pheochromocytomas, paragangliomas, neuroblastomas and ganglioneuromas, including approaches based on PET with [(18)F]fluorodopamine, [(18)F]fluorohydroxyphenylalanine, [(11)C]epinephrine or [(11)C]hydroxyephedrine. Such functional imaging can complement computed tomography or magnetic resonance imaging and other scintigraphic techniques to localize these tumors before surgical or medical therapeutic approaches are considered.

The diagnosis and medical management of advanced neuroendocrine tumors

Neuroendocrine tumors (NETs) constitute a heterogeneous group of neoplasms that originate from endocrine glands such as the pituitary, the parathyroids, and the (neuroendocrine) adrenal, as well as endocrine islets within glandular tissue (thyroid or pancreatic) and cells dispersed between exocrine cells, such as endocrine cells of the digestive (gastroenteropancreatic) and respiratory tracts. Conventionally, NETs may present with a wide variety of functional or nonfunctional endocrine syndromes and may be familial and have other associated tumors. Assessment of specific or general tumor markers offers high sensitivity in establishing the diagnosis and can also have prognostic significance. Imaging modalities include endoscopic ultrasonography, computed tomography and magnetic resonance imaging, and particularly, scintigraphy with somatostatin analogs and metaiodobenzylguanidine. Successful treatment of disseminated NETs requires a multimodal approach; radical tumor surgery may be curative but is rarely possible. Well-differentiated and slow-growing gastroenteropancreatic tumors should be treated with somatostatin analogs or alpha-interferon, with chemotherapy being reserved for poorly differentiated and progressive tumors. Therapy with radionuclides may be used for tumors exhibiting uptake to a diagnostic scan, either after surgery to eradicate microscopic residual disease or later if conventional treatment or biotherapy fails. Maintenance of the quality of life should be a priority, particularly because patients with disseminated disease may experience prolonged survival.