SAT-216 Retroperitoneal Paraganglioma: Case Report

Introduction: Paraganglioma (PGL) is a rare type of neuroendocrine neoplasm able to secrete neuropeptide and catecholamines. It can occur in any location between the neck and the pelvis. Most of the PGLs are diagnosed in the third to fifth decades and clinical presentation is variable and depends upon catecholamine secretion and tumor location. PGLs occur in the abdomen in 85% of cases. There are no unique imaging characteristics specific for PGLs, consequently, these tumors can be mistaken with other primary abdominal tumors. Clinical-Case: We present the case of a 65-year-old woman with history of hypertension (diagnosis at 40 years) and dyslipidemia. She denied family history of hypertension. In the context of a recent diagnosis of type 2 Diabetes Mellitus, she underwent abdominal ultrasound which revealed a large, heterogeneous nodular formation with partial liquid content, measuring 12x15 cm, adjacent to the left hepatic border. Abdominal CT scan revealed an intra-abdominal mass, with 14cm (largest diameter), showing intimate contact, with no cleavage plan with the posterior wall of the gastric fundus, suggesting Gastrointestinal Stromal Tumor. A left adrenal nodule with 3.3 cm was also present, rounded, hypoechogenic, with regular margins and homogeneous. Echoendoscopy with biopsy of the retro-gastric mass showed a neuroendocrine neoplasia. At this point she was sent to an endocrinologist. When questioned she referred headache, diaphoresis and anxiety complaints for 3 years. At examination, a painless abdominal mass in the epigastrium and left hypochondrium was found. Laboratory evaluation revealed urinary metanephrines 11738 (64-302) ug/day, urinary normetanephrines 5832 (162-527) ug/day, renin 15.5 (1-8.2) pg/mL, aldosterone 28.6 (10-160)ng/dL, cortisol after 1 mg dexamethason 1,18 µg / dl (less than 1,8ug/dl) and chromogranin A 36.6 nmol / L (less than 3nmol/l). MIBG scintigraphy revealed fixation only in the large known retroperitoneal mass. The patient underwent excision of the retroperitoneal mass and of the left adrenal gland without complications. The histological diagnosis revealed, respectively, paraganglioma and adrenal cortical adenoma. Four weeks after surgery laboratory results were normal (urinary metanephrines 202 ug/24h and normetanephrines 382.0 ug /day; Chromogranin A 2.60 nmol/l). The results of the genetic tests including SDHB, SDHD, SDHC, VHL and MAX were negative. Conclusion: This report emphasizes the necessity to include paraganglioma in the differential diagnosis and management of retroperitoneal tumors avoiding the risk of the biopsy in this kind of tumors.