S2931 A Rare Histologic Sub-Type of Mucinous Gastric Adenocarcinoma (MGC) in Liver Transplant Recipient

Abstract

INTRODUCTION: The relationship between solid organ transplant recipients and development of de novo malignancies has been well established in the literature. Liver transplant recipients have a 20% risk of developing de novo malignancies at 10 years post-transplant, which increases to 55% at 15 years post-transplant. Most commonly, de novo malignancies in liver transplant recipients include lymphoproliferative disorder, non-Hodgkin Lymphoma, head and neck cancer, Kaposi Sarcoma, and esophageal carcinoma. CASE DESCRIPTION/METHODS: A 73 yo M from West Africa, non-smoker, with no reported EtoH/IVD use, h/o liver transplant in a setting of HBV liver disease on immunosuppressive therapy, h/o prostate cancer s/p prostatectomy, presented with complaint of dizziness, fatigue and tarry black stool for 1–2 weeks. The patient was found to have microcytic anemia with Hgb of 4.6 g/dL. He was admitted to ICU and pRBC transfusion. EGD showed likely malignant gastric tumor in the gastric antrum involving the incisura and extending to the pylorus and proximal duodenal bulb causing luminal narrowing (see images below). Labs were positive for slightly elevated CEA of 6.2 ng/mL. CT abdomen/pelvis showing thickening of gastric wall and enlarged celiac lymph node. Biopsy revealed MGC negative for HER2. DISCUSSION: MGC is a very rare subtype of undifferentiated gastric carcinoma, constituting 2–6% of all gastric cancers. WHO defines MGC as adenocarcinoma with >50% of extracellular mucin within tumors. Of the several mucin types, MUC2 was found to be strongly associated to MGC. It has been known that HER-2 and EGFR are poor prognostic indicators in stomach cancer patients, their clinical importance have not been investigated. The tumor size, macroscopic type, depth of invasion, lymph node metastasis, peritoneal metastasis and hepatic metastasis but not histological type, are significant predictive factors for survival. On review of the literature, we found that patients with MCG had more metastatic lymph node involvements and venous invasion compared to NMGCs. In addition to surgery, therapeutic agents that target oncogenes have attracted much attention. Anti-HER-2 monoclonal antibody(mAb) and an anti-EGFR mAb, have reached the clinical trial stage for gastric cancer treatments.Reports of gastric adenocarcinoma in liver transplant recipients appear in the literature as case reports or case series. This case highlights the importance of increasing index of suspicion for gastric malignancy in liver transplant recipients.Figure 1Figure 2