case_images: PMC4929366_01
case_images: Endoscopic appearance of the appendiceal adenocarcinoma. a A single frond-like villous polyp was present in the rectal lumen and appeared to be located within a diverticulum. b The mucosal pattern appeared distorted, consistent with malignancy.
case_images: crg-0010-0024-g01.jpg
case_images: PMC4929366_01_crg-0010-0024-g01.jpg
case_images: F1
case_images: A follow-up colonoscopy was then performed 2 months later which noted a single frond-like, villous, broad-based rectal polyp that appeared to be located within a diverticulum (fig. 1a), and which had an area of distorted mucosal pattern consistent with malignancy (fig. 1b).
case_images: Preoperative CT scan demonstrating a dilated appendix abutting the right side of the rectal wall.
case_images: crg-0010-0024-g02.jpg
case_images: PMC4929366_01_crg-0010-0024-g02.jpg
case_images: F2
case_images: A preoperative CT scan demonstrated a dilated appendix with its tip near the rectum which was of unclear significance at that time (fig. 2).
case_images: An en bloc resection of the appendix and rectum was performed. The appendix is densely adherent to the rectal wall along the right side and is dilated at its tip.
case_images: crg-0010-0024-g03.jpg
case_images: PMC4929366_01_crg-0010-0024-g03.jpg
case_images: F3
case_images: En bloc resection of the distal sigmoid colon and proximal rectum together with the appendix was performed (fig. 3).
case_images: Anatomic evaluation of the resected specimen. A mass lesion was identified in the tip of the appendix, with direct extension into the lumen of the rectum at the site of the presumed rectal polyp.
case_images: crg-0010-0024-g04.jpg
case_images: PMC4929366_01_crg-0010-0024-g04.jpg
case_images: F4
case_images: The proximal appendix was normal in appearance (fig. 4).
case_images: Histological evaluation of the resected specimen. Direct invasion of the appendiceal adenocarcinoma into the rectal lumen was confirmed histologically.
case_images: crg-0010-0024-g05.jpg
case_images: PMC4929366_01_crg-0010-0024-g05.jpg
case_images: F5
case_images: Pathology showed adenocarcinoma arising focally within an appendiceal tubulovillous adenoma with direct invasion into the rectum (fig. 5).