Do get suspicious: diagnosing appendicular goblet cell carcinoid

Abstract

A 71-year-old male with asymptomatic iron deficiency anaemia underwent elective endoscopy. Colonoscopy revealed sigmoid diverticulosis and an unusual appearing, ‘pouting’ appendicular orifice with normal overlying mucosa (Fig. 1). Histology results demonstrated a Tang B, signet ring cell type, adenocarcinoma ex goblet cell carcinoid (GCC). Computed tomography demonstrated a normal appearing appendix without hepatic or pulmonary lesions. Repeat biopsies were performed for confirmation due to disease rarity and a normal looking appendix. Following multidisciplinary team discussion, a right hemicolectomy was performed with oncological margins. Final histology showed involvement of the entire appendix with perineural and lymphovascular invasion with extension into the mesoappendix. Macroscopically normal tissue from the cecum at the base of appendix was infiltrated and mesocolic lymph node metastases were present (pT4aN1M0R0). Post-operatively, he was commenced on adjuvant Oxaliplatin and Fluorouracil. He will undergo 6 monthly clinical examination and computed tomography. Goblet cell appendiceal carcinomas are also called mixed adenoneuroendocrine carcinomas as they contain both epithelial and neuroendocrine cells. Incidence is 3–5% of primary appendicular tumours. The expression of markers including CK20, CDX-2, CD56 assists diagnosis. Tissue may stain for chromogranin or synaptophysin. Five-year mean survival varies from 15–60% in the absence of metastatic disease. Tang developed a classification with three histological subtypes. Adenocarcinoma ex-goblet cell carcinoid frequently exhibits aggressive behaviour with peritoneal/intra-abdominal dissemination. Presentation with stage III/IV disease with spread to right colon, peritoneal surfaces and ovary occurs in 51–97%. The choice of surgical procedure (appendicectomy versus hemicolectomy) is dependent upon histology and disease extent. Median age of diagnosis is the fifth decade of life. Presentations include: acute appendicitis (approximately 23%), non-localized abdominal pain (5%) and appendicular mass (3%). Up to 5% are asymptomatic. In our case, a high degree of clinical suspicion on the part of the endoscopist resulted in timely diagnosis and treatment of this patient.