Contributed by Sonal Kamat, MD
68 year old female presented with acute appendicitis. She had chief complaints of fever, nausea, vomiting and abdominal pain which had got worse 2 days before admission. Her past medical history was positive for hypertension. She underwent an emergency appendicectomy as she had developed signs of peritonitis.
A 7.0x1.5 cm specimen of appendicectomy was received. The appendix was perforated. The serosa was covered by a grey white fibrinous exudate. No grossly identifiable solid lesion was noted.
Histopathological examination showed acute perforative appendicitis (images 1 and 2). Also seen were small uniform nests and clusters of signet ring cells predominantly submucosal in location and infiltrating the muscularis propria with focal extension to the subserosal layer (images 3, 4 and 5). These were located close to the site of perforation of the appendix. The size of the tumor was less than 2cm. Proximal and serosal resection margins were free of tumor.
Immunohistochemical studies showed that the neoplastic cells positive for synaptophysin and focally positive for Cytokeratin 20, Cytokeratin 7, Carcinoembryonic Antigen and Mucicarmine (image 6).