Pheochromocytoma and Paraganglioma: From Clinical Findings to Diagnosis

Özet

The majority of pheochromocytoma (PCC) and paraganglioma (PGL) are endocrine active tumors, and they cause clinical symptomsby secreting excess one or more catecholamines (epinephrine, norepinephrine, and dopamine) and their inactive metabolites(metanephrine, normetanephrine, 3-metoxythromine). Although signs and symptoms regarding excess catecholamine oftendevelop in PCC and PGL (PPGL), non-functional PPGLs may present with local compression symptoms. Persistent, sometimesworsening hypertension is the most common finding and occurs in 80-90% of the patients. Classically defined symptom triad;headache, sweating and palpitations are seen in only 25% of the patients with PCC. The difference of clinical symptoms may berelated to the tumor secretion, epinephrine or norepinephrine. All patients with signs and symptoms suggestive of catecholamineexcess should be screened by biochemical tests regardless of whether they have hypertension or not. Not all patients with newlydiagnosed hypertension need to be screened, but only patients with additional tips for catecholamine excess should be screened.Approximately 20% of the PPGLs are diagnosed in childhood, and the male/female ratio is 2/1. 60-90% of pediatric patients presentwith hypertension. PPGL in pregnancy is rare, and the estimated incidence ranges between 1/15000-1/54000. Although earlydiagnosis is the most important factor in preventing mortality, diagnosis is not as easy as it is a rare condition. Hypertension is acommon complication in pregnancy, occurring in 5-10%. Computed tomography should not be used as the imaging method duringpregnancy; the first choice is magnetic resonance imaging with gadolinium or without contrast. Plasma free metanephrine or24-hour urinary fractionated metanephrine level is recommended as a screening test for the diagnosis of PPGL in the EndocrineSociety Clinical Practice Guideline. In suspicious situations, tests should be repeated. Since 40% of these patients have germlinemutations, genetic tests are recommended for all patients with PPGL regardless of family history and age. Preoperative knowledgeof germline mutations affects the surgical approach and the extent of adrenalectomy. After the biochemical diagnosis is made inPPGL, the tumor is localized with imaging methods to make the operation plan. In this review, we aimed to evaluate the clinicalfindings, diagnostic tests, and imaging studies for tumor localization in PPGL.