Mucinous adenocarcinomas of the appendix are at the malignant end of the spectrum of the mucinous neoplasms that affect the cecal appendix.
The peak incidence is in the 6th and 7th decades 1,3. Associations with other colonic neoplasms and chronic ulcerative colitis have been reported 1.
Symptoms are much more likely to manifest than in the other more indolent appendiceal neoplasms (e.g. adenoma or neuroendocrine tumors). The spectrum of symptoms varies from vague abdominal pain, nausea, vomiting, and weight loss, to a palpable mass, abdominal distension, and acute appendicitis 1,3.
Considerable controversy still exists regarding mucinous neoplasms of the appendix pathologic classification and nomenclature 1. According to a panel of specialist review in 2016, a new nomenclature and classification for the appendiceal mucinous neoplasms based on their histologic type and biologic behavior has been proposed and since then the term mucinous adenocarcinoma should be reserved for those mucinous tumors with infiltrative invasion beyond the muscularis mucosa 1,2.
An adenocarcinoma is defined as mucinous when extracellular mucin corresponds to more than 50% of the lesion. The signet ring cell carcinoma variant occurs when a tumor has more than 50% of cells showing the classical signet ring morphology 1,2.
Non-specific signs may indicate a tumoral lesion adjacent to the cecum, including the non-filling of the appendix, a submucosal mass lesion at the cecal pole, and an extraluminal compression of the cecum 1.
Treatment and prognosis
- 1. Tirumani SH, Fraser-Hill M, Auer R, Shabana W, Walsh C, Lee F, Ryan JG. Mucinous neoplasms of the appendix: a current comprehensive clinicopathologic and imaging review. Cancer imaging : the official publication of the International Cancer Imaging Society. 13: 14-25. doi:10.1102/1470-7330.2013.0003 - Pubmed
- 2. Carr NJ, Cecil TD, Mohamed F, Sobin LH, Sugarbaker PH, González-Moreno S, Taflampas P, Chapman S, Moran BJ. A Consensus for Classification and Pathologic Reporting of Pseudomyxoma Peritonei and Associated Appendiceal Neoplasia: The Results of the Peritoneal Surface Oncology Group International (PSOGI) Modified Delphi Process. The American journal of surgical pathology. 40 (1): 14-26. doi:10.1097/PAS.0000000000000535 - Pubmed
- 3. Leonards LM, Pahwa A, Patel MK, Petersen J, Nguyen MJ, Jude CM. Neoplasms of the Appendix: Pictorial Review with Clinical and Pathologic Correlation. Radiographics : a review publication of the Radiological Society of North America, Inc. 37 (4): 1059-1083. doi:10.1148/rg.2017160150 - Pubmed
Related Radiopaedia articles
The appendix can be affected by numerous inflammatory, infectious and neoplastic conditions:
- appendiceal diverticulitis
- appendiceal mucocele
- appendiceal intussusception
neoplasms of the appendix
- appendiceal epithelial neoplasms
- Goblet cell carcinoid of the appendix
- appendiceal neuroendocrine tumors
- appendiceal lymphoma