S1575 Isolated Gastrointestinal Gangliocytic Paraganglioma

Abstract

Introduction: Gangliocytic paragangliomas of the GI tract are neuroendocrine tumors located in the second portion of the duodenum. Isolated gastrointestinal paragangliomas are rare, as paragangliomas are often associated with genetic conditions, including Von Recklinghausen disease (NF1) and Paraganglioma-Pheochromocytoma Syndrome (HPPS). We present the case of a 45 year-old woman --without the aforementioned hereditary conditions-- with symptomatic anemia found to have an ulcerated ampullary paraganglioma. Case Description/Methods: Our patient is a 45 year-old woman with a medical history of iron deficiency anemia and a remote cholecystectomy who presented with a four day history of melena, weakness, palpitations, and dyspnea. Her exam did not reveal epigastric tenderness, abdominal pain, rebound or guarding. Labs were notable for a microcytic anemia (Hgb: 3.4 g/dl) without transaminitis or elevated lipase. She was transfused 5 units packed red blood cells with appropriate response. A CT abdomen/pelvis was normal. Colonoscopy was without evidence of bleeding. Enteroscopy revealed a large mass in the second portion of the duodenum adjacent to the Ampulla of Vater. EUS characterized the mass as a well defined, hypoechoic submucosal lesion measuring 3 cm, without extension to the common bile duct and pancreatic duct. Fine needle biopsy revealed rare atypical spindle cells with high S-100 positivity. The patient underwent resection with a transduodenal ampullectomy. Surgical pathology demonstrated a 3.8 cm ampullary gangliocytic paraganglioma. Further genetic testing for HPPS was negative (FH, MAX, MEN1, NF1, RET, SDHA, SDHAF2, SDHB, SDHC, SDHD, TMEM127, VHL). She did not have evidence of upregulated hormonal activity, with normal levels of 24 hour urine metanephrines, TSH, and renin/aldosterone. Discussion: Gastrointestinal gangliocytic paragangliomas require a comprehensive work-up beyond fine needle biopsy to achieve a diagnosis. EUS/FNA is often inconclusive, as spindle cell predominance on cytology can mimic a schwannoma, necessitating further tissue sampling and/or resection. In addition, genetic testing and hormonal lab work is favored to rule out associated conditions such as NF1 and HPPS. Our patient’s diagnosis was made after transduodenal ampullectomy as the initial fine needle biopsy did not contain ganglion and epithelioid cells, additional neural crest derivatives. Post operatively, genetic and hyperadrenal testing were noncontributory, confirming the diagnosis of an isolated paraganglioma.Figure 1.: Large, submucosal mass in the second portion of the duodenum with 2 areas of surface ulceration. Lesion is close in proximity but not in direct continuity to the ampullary orifice.