S2929 Ruptured Gastric Cancer Presents As Cardiac Tamponade with Exophytic Liver Lesion Disguised As Echinococcus

INTRODUCTION: Cardiac tamponade due to a ruptured primary gastric adenocarcinoma is rare, and usually occurs due to advanced metastatic disease involving the pericardium and visceral organs. A large exophytic hepatic lesion in a patient of Tibetan ethnicity might lead physicians to also consider an infectious etiology like echinococcus, tuberculosis, or an abscess. We present a rare presentation of ruptured gastric adenocarcinoma with pericardial and liver involvement, unexpectedly without evidence of metastasis. CASE DESCRIPTION/METHODS: A 53 y.o. Tibetan man with no past medical history presented to a city hospital with 3 weeks of epigastric pain, weight loss and exertional dyspnea. Exam showed mild epigastric tenderness without stigmata of chronic liver disease or jaundice. Labs significant for hepatocellular liver injury and leukocytosis (Table 1), with negative liver diseases workup. Abnormal EKG prompted TTE demonstrating increasing pericardial effusion. The patient underwent emergent pericardial drain placement for cardiac tamponade at a tertiary center. He started empiric antibiotics, including albendazole to treat presumed echinococcus, which has up to a 10% prevalence in Tibetan populations. Pericardial cytology showed acute inflammation, without malignant cells (Table 1). CT Chest Abdomen Pelvis with contrast (Figures 1 and 2) after drainage showed a “decrease in size of a 7.7 cm heterogeneous non-enhancing hepatic lesion inseparable from the pericardium, most likely inflammatory intrahepatic mass such as echinococcus with rupture into the pericardium”. Exploratory laparotomy revealed an 8 cm poorly differentiated gastric adenocarcinoma perforating the serosa; the liver and pericardium had extensive inflammatory changes without evidence of carcinoma or echinococcus. The patient underwent distal gastrectomy, left liver resection, and pericardial window. Liver tests normalized upon resection. DISCUSSION: Gastric cancer is the 5th most common cancer worldwide. Pertinent personal risk factors included male sex, Tibetan ethnicity, smoking history and consumption of smoked foods. While prior literature reports a handful of cases of pericarditis carcinomatosa originating from gastric cancers, we report a unique presentation of invasive gastric carcinoma with clinically significant inflammatory reaction in the liver and pericardium, without metastases. This cancer is categorized as AJCC Stage IIIA pT4aN1M0 with plan for treatment as intent to cure with CAPOX (capecitabine and oxaliplatin) after surgery.Table 1.: Laboratory, Imaging and Data. All data from admission and initial work-up unless stated. Key: (H) = High; (L) = Low.Figure 1.: CT Chest Abdomen Pelvis with contrast from city hospital This CT Chest transverse venous phase view of the pericardium demonstrates large pericardial effusion.Figure 2.: CT Chest Abdomen Pelvis with contrast from tertiary center This CT Abdomen transverse venous phase view demonstrates patchy infiltrate of the liver with re-demonstration of a 7.7 × 6.7 × 5.2 cm heterogenous non-enhancing exophytic mass arising off segment 2 of the liver. There is no clear separation between this exophytic liver mass and the pericardium. The radiologist notes there is no evidence of active arterial extravasation within the mass to suggest acute bleeding.