Literature Review About Pheochromocytoma PDF

LITERATURE REVIEW ABOUT PHEOCHROMOCYTOMA BY: Kerollos George Nassef Objectives 1.introduction 2.causes 3.symptoms 4.diagnosis 5.treatment 6.summary 7.references Introduction Pheochromocytoma is a rare neuroendocrine tumor that originates from the chromaffin cells of the adrenal medulla...

LITERATURE REVIEW ABOUT PHEOCHROMOCYTOMA BY: Kerollos George Nassef Objectives 1.introduction 2.causes 3.symptoms 4.diagnosis 5.treatment 6.summary 7.references Introduction Pheochromocytoma is a rare neuroendocrine tumor that originates from the chromaffin cells of the adrenal medulla. These tumors are characterized by the excessive production of catecholamines, including adrenaline and noradrenaline, which can lead to severe cardiovascular symptoms. Although pheochromocytomas are usually benign, they can cause significant morbidity and, if undiagnosed or untreated, can be life-threatening. Causes The exact cause of pheochromocytoma is often unknown. However, a significant proportion of cases are associated with genetic mutations and familial syndromes. Approximately 30-40% of pheochromocytomas are linked to hereditary conditions such as: Multiple Endocrine Neoplasia type 2 (MEN2) Von Hippel-Lindau disease (VHL) Neurofibromatosis type 1 (NF1) Succinate dehydrogenase (SDH) gene mutations Symptoms Hypertension (sustained or paroxysmal) Severe headaches Palpitations Sweating Tachycardia Anxiety or panic attacks Abdominal pain Weight loss These symptoms result from the excessive release of catecholamines and can be episodic, leading to diagnostic challenges. Diagnosis The diagnosis of pheochromocytoma involves a combination of biochemical tests and imaging studies. Key diagnostic steps include: 1. Biochemical Testing: Measurement of plasma-free metanephrines or urinary fractionated metanephrines, which are the most sensitive and specific tests. Catecholamine levels in plasma or urine can also be measured. 2. Imaging Studies: Computed Tomography (CT): A CT scan of the abdomen and pelvis is often the first imaging modality used to locate the tumor. Magnetic Resonance Imaging (MRI): MRI can be used when CT is inconclusive or if there is a need to avoid radiation. Metaiodobenzylguanidine (MIBG) Scintigraphy: This is particularly useful in detecting extra-adrenal or metastatic pheochromocytomas. Treatment The treatment of pheochromocytoma primarily involves surgical resection of the tumor. However, preoperative management is crucial to control hypertension and prevent intraoperative complications. Key treatment steps include: 1. Preoperative Management: Alpha-blockade: To control blood pressure and prevent hypertensive crises, patients are usually started on alpha-blockers (e.g., phenoxybenzamine) several days to weeks before surgery. Beta-blockade: Added after adequate alpha-blockade if tachycardia persists. 2. Surgical Resection: The definitive treatment is the surgical removal of the tumor, often performed laparoscopically if the tumor is localized and not too large. For malignant or metastatic cases, complete resection may not be possible, and additional treatments such as chemotherapy, radiation, or targeted therapies may be necessary. 3. Postoperative Follow-up: Continuous monitoring of blood pressure and catecholamine levels is essential to detect any recurrence or residual disease. Summary of Pheochromocytoma Pheochromocytoma is a rare tumor from the adrenal medulla causing excessive adrenaline and noradrenaline production. It can be linked to genetic conditions like MEN2, VHL, NF1, and SDH mutations. Symptoms include hypertension, headaches, palpitations, sweating, tachycardia, anxiety, abdominal pain, and weight loss. Diagnosis involves measuring plasma-free metanephrines or urinary metanephrines and imaging with CT, MRI, or MIBG scintigraphy. Treatment includes preoperative blood pressure control with alpha and beta-blockers, surgical tumor removal, and postoperative monitoring for recurrence. References 1. Lenders, J. W. M., Eisenhofer, G., Mannelli, M., & Pacak, K. (2005). Phaeochromocytoma. The Lancet, 366(9486), 665-675. 2. Fishbein, L., Leshchiner, I., Walter, V., Danilova, L., Robertson, A. G., Johnson, A. R., … & Nathanson, K. L. (2017). Comprehensive molecular characterization of pheochromocytoma and paraganglioma. Cancer Cell, 31(2), 181-193. 3. Neumann, H. P. H., Young, W. F., Eng, C. (2019). Pheochromocytoma and Paraganglioma. The New England Journal of Medicine, 381(6), 552-565. 4. Mannelli, M., Lenders, J. W. M., Pacak, K. (2012). Subclinical Pheochromocytoma. Best Practice & Research Clinical Endocrinology & Metabolism, 26(4), 507-515.