Aliana Bofill, MD1, Zeyn Mirza, MD2, Rodolfo Estremera, MD2, Jose Martin2
1VA Caribbean Healthcare System, San Juan, Puerto Rico; 2VA Hospital, San Juan, Puerto Rico
Introduction: Neuroendocrine tumors (NETs) of the ampulla of Vater represent less than 0.3% of gastrointestinal NETs and less than 2% of all periampullary malignancies. There are approximately 139 cases in literature, making this rare condition a diagnostic challenge. Jaundice is the predominant symptom followed by abdominal pain. Acute pancreatitis as the initial presentation has seldom been reported. Herein we report a case of a patient who presented with acute pancreatitis and biliary obstruction secondary to an ampullary NET.
Case Description/Methods: Case of a 74-year-old male with hypertension who reported burning epigastric pain. Denied fever, vomits, weight loss, diarrhea, flushing or dyspnea. Physical examination with epigastric tenderness. Laboratories showed elevated alkaline phosphatase 398 U/L, total bilirubin 3.4 mg/L, lipase 594 U/L and amylase 216 U/L. Contrast abdominopelvic CT showed a duodenal periampullary mass with common bile duct measuring 1.1 cm and intrahepatic and extrahepatic dilatation. Endoscopic retrograde cholangiopancreatography (ERCP) revealed an irregular, ulcerated ampullary mass. Biopsy showed poorly differentiated carcinoma. Immunostains were positive for chromogranin, synaptophysin, CK7, weakly positive for CDX-2. Negative for TTF-1 and CK20. Octreotide scintigraphy with no uptake. Somatostatin, chromogranin, and 5-hydroxy-in-dole acetic acid were normal. Patient underwent surgical treatment with pancreaticoduodenectomy.
Discussion: The rarity of ampullary NETs and its proliferation under an intact mucosa makes it difficult to detect in biopsy. Most of the time the diagnosis is based on histology and preoperative diagnosis may be challenging since they clinically present like adenocarcinoma. The usual presentation of jaundice and abdominal pain places this diagnosis low on the differential. In our case, the unusual morphologic appearance likely facilitated obtaining an assertive pre-operative diagnosis. Our patient presented with obstructive jaundice and acute pancreatitis, which occurs in less than 6% of cases. The clinical picture of ampullary NETs is easily confounded given the associated symptoms and biopsy challenges. A high index of suspicion is paramount to ensure this rare diagnosed is not missed. Pancreaticoduodenectomy has been advocated as the treatment of choice regardless of size due to high risk of occult nodal metastases. Considering this diagnosis within the differential is important given the drastically different outcomes for patients if caught early.
Citation: Aliana Bofill, MD; Zeyn Mirza, MD; Rodolfo Estremera, MD; Jose Martin. P2640 - SECRETS OF THE AMPULLA: A RARE NEUROENDOCRINE TUMOR. Program No. P2640. ACG 2019 Annual Scientific Meeting Abstracts. San Antonio, Texas: American College of Gastroenterology.