S1533 An Unusual Presentation of a Rare Ampullary Neoplasia

Abstract

INTRODUCTION: Ampullary neoplasias are uncommon, with most tumors being of pancreaticobiliary or intestinal origins. SRCC of the Ampulla of Vater is an extremely rare variant of adenocarcinoma with only 38 previously cases reported in the literature. Little is known about the pathogenesis, treatment, and outcomes of this uncommon subtype. We report a case of ampullary SRCC in a patient who presented with a TIA and choledocholithiasis. CASE DESCRIPTION/METHODS: An 83-year-old lady was brought to the hospital with one day of slurred speech and right-sided weakness. Stroke workup was negative, her symptoms resolved rapidly, and she was diagnosed with a TIA. GI service was consulted for elevated liver enzymes. Patient reported decreased appetite for a few weeks with some weight loss. Denied fevers, chills, nausea, vomiting, jaundice, pruritis, dark urine, pale stools, new medications, alcohol abuse, or Tylenol use. She was a 15-pack year active smoker. On exam, she was afebrile with stable vitals and mild epigastric tenderness. Lab work up showed WBC 15.9 with a left shift. CMP noted TBili 3.6 (Conjugated 1.4), AST 442, ALT 260, ALP 645, Lipase 57. RUQ US showed cholelithiasis and a dilated CBD (7.3 mm). MRCP revealed mild diffuse intrahepatic and extrahepatic biliary dilatation, multiple small stones within a 1.6cm CBD with appropriate tapering at the ampulla. ERCP revealed 2-3 cm nodular cratered ulceration with irregular heaped up margins adjacent to the Ampulla of Vater. Patient underwent papillotomy, stone extraction, and placement of a fully covered wall stent. Tumor markers noted CA19-9 of 50. Pathology showed infiltrating poorly-differentiated adenocarcinoma with signet-ring cell features of the Ampulla of Vater. Tumor cells were positive for CK7, CK19, CK20, CDX2, pan keratin, MUC-1, MUC-2; and negative for MUC-6 by immunohistochemistry (IHC). After extensive discussion of findings, treatments options with multidisciplinary team including surgical oncology and palliative care services, patient declined surgical intervention and decided to spend her remaining days at home. DISCUSSION: A signet-ring variant of the adenocarcinoma of the Ampulla of Vater is an extremely rare neoplasm. This is a unique case of a lady with concomitant choledocholithiasis incidentally found to have SRCC of the Ampulla of Vater. Given the rarity of these cases, special staining and IHC will add to our knowledge of the origins of these neoplastic cells and help tailor future therapeutics.Figure 1.: Histological examination of biopsied specimen in high power view showing atypical infiltrating cells with eccentric nuclei and intra-cytoplasmic mucin.Figure 2.: Histological examination showing adenocarcinoma with characteristic signet ring cells.Figure 3.: Histological examination at lower power with signet ring cell adenocarcinoma tumor infiltration.