Alyssa Mowrer, MD, Clayton Theleman, MD, Thomas Rossi, MD, FACS. University of Illinois College of Medicine at Peoria
Introduction: Neoplasms of the appendix occur in less than 1% of all appendectomy specimens. Mucoceles of the appendix are mucin filled cystic lesions that are classified as either benign, a cystadenoma, or malignant, a cystadenocarcinoma. Rupture of mucoceles of the appendix is associated with peritoneal tumor implantation and mucinous ascites; a condition known as pseudomyxoma peritonei that carries a median 10-year survival rate of only 63%. Although the medical approach for mucinous neoplasms has been somewhat controversial, the standard of care remains prompt surgical resection.
Case Description: A 49-year-old female presented with 3 days of periumbilical abdominal pain. She described nausea with emesis, decreased bowel function, and an acute weight loss of 10 pounds since onset of symptoms. A CT scan demonstrated appendiceal intussusception.
Figure 1: Dilated, fluid filled, blind ending structure measuring 4 cm in diameter consistent with the appendix.
The patient was then taken to the operating room for resection. Due to the high clinical suspicion for an appendiceal tumor and significant risk of pseudomyxoma peritonei with rupture of an appendiceal mucocele, an open approach to a right hemicolectomy was planned. A firm mass palpated within the cecum at the base of the appendix was found to be inspissated mucin from the tumor. The specimen was removed intact.
Figure 2: Surgical specimen including appendix and right colon with intussusception of appendiceal base into cecum.
Final pathology was consistent with a low grade appendiceal mucinous neoplasm that extended through the muscularis propria and into peri-appendicular tissue.
Figure 3: Tumor with mild cytologic atypia. Cellular mucin goblets extruding into appendiceal lumen. Histologic grade 1 (well differentiated) and stage T3N0M0.
Discussion: This case of a suspected mucocele of the appendix was complicated by the presentation of appendiceal intussusception. With a devastating possible complication of rupture of the appendiceal mucocele seeding the peritoneum and progressing to pseudomyxoma peritonei, we elected to perform an open approach. Although there have been case reports discussing endoscopic reduction of an appendiceal intussusception, this patient presented with partial obstructive symptoms which contributed to the decision for first line intervention with operative management.
At this point, there is limited information in the literature involving the extremely rare combination of an appendiceal mucocele with the clinical presentation of an obstruction at an intussuscepted appendix. We hope to contribute to the growing body of literature to provide the general surgeon with recommended guidelines when presented with this unusual clinical scenario.
Presented at the SAGES 2017 Annual Meeting in Houston, TX.
Abstract ID: 91621
Program Number: P028
Presentation Session: Poster Session (Non CME)
Presentation Type: Poster