S1771 Right Lower Quadrant Abdominal Pain: Time to Think Beyond Acute Appendicitis

Abstract

INTRODUCTION: Incidence of primary appendiceal carcinoma is less than 1% amongst all gastrointestinal malignancies. Goblet cell carcinoma (GCC) accounts for less than 14% of all the appendiceal tumor, with an annual incidence rate of 0.05/100,000 per year. We present a case of goblet cell carcinoma who presented with lower abdominal pain. CASE DESCRIPTION/METHODS: 75-year-old lady with a PMH of frequent diverticulitis presented to ED for left lower quadrant (LLQ) abdominal pain that later migrated to right lower quadrant (RLQ). Physical examination revealed tenderness over the RLQ. Lab work revealed leukocytosis. CT abdomen showed inflammatory stranding in the right paracolic gutter and mildly dilated appendix, extensive left colon diverticulosis. Diagnostic laparoscopy revealed sigmoid diverticulitis, purulent fluid in right paracolic gutter and inflamed appendix. Appendectomy was done and biopsy revealed goblet cell carcinoma with TANG B histology. Final staging was pT3pNx with Ki67 of 40%. Immunohistochemical staining was positive for CK-7, synaptophysin and weakly positive for CD-56. CA 125 was high. Further imaging and colonoscopy ruled out metastasis or synchronous disease. Within 3 weeks she relapsed at trocher site. Repeat PET CT showed LLQ nodularity, RLQ fluid collection and activity in the liver indicating possible carcinomatosis. Patient was started on Folfox. DISCUSSION: GCC shares common histological characteristics of both adenocarcinoma and carcinoid tumor with intermediate aggressive behavior. Initial presentation is usually abdominal pain but can present with pelvic mass, abdominal distension, bleeding and genitourinary complications. GCC are usually weakly positive or negative for Chromogranin A and synaptophysin so somatostatin scintigraphy scan is usually not helpful. CEA, CA-125, and Ca19-9 are recommended as the markers for diagnosis and follow up. Surgery is the ultimate treatment, but debate persists between appendectomy vs right hemicolectomy. Right hemicolectomy is recommended for high grade TANG group B and C disease. Since metastatic disease mostly resembles adenocarcinoma 5-FU and leucovorin are usually advised. Prognosis is poor with average survival rate being 4.6 years. Diagnosis and management of GCC is challenging due to unpredictable biological behavior and scarcity of data. Guidelines about extent of surgical resection, role of chemotherapy, follow up protocol and role of aggressive peritoneal management need to be elucidated with prospective trial studies.