Mucinous adenocarcinoma of the appendix

Mucinous adenocarcinomas of the appendix are on the malignant end of the spectrum of the mucinous neoplasms that affect the caecal appendix

For the mucinous carcinomas involving the remainder of the colon, please refer to the article on mucinous carcinoma of the colon.

Peak incidence in the 6th and 7th decades 1,3. Associations with other colonic neoplasia and chronic ulcerative colitis have been reported 1

Symptoms are much more likely to happen than in the other more indolent appendiceal neoplasms (e.g. adenoma or neuroendocrine tumours). The spectrum of symptoms varies from a vague abdominal pain, nausea, vomiting, and weight loss, to a palpable mass, abdominal distension, and acute appendicitis 1,3.

Considerable controversy still exists on 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 behaviour has been proposed and since then the term mucinous adenocarcinoma should be reserved for the mucinous tumours that have an 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 tumour has more than 50% of cells showing the classical signet ring morphology 1,2.  

Nonspecific signs may indicate a tumoural lesion adjacent to the caecum, including the non-filling of the appendix, a submucosal mass lesion at the caecal pole, and an extraluminal compression of the caecum 1

Staging and management of these are different from those of colorectal carcinoma, please refer to the appendiceal mucinous neoplasms TNM staging for further details. 

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Article information

rID: 54968
Section: Pathology
Synonyms or Alternate Spellings:
  • Mucinous adenocarcinoma of the appendix
  • Appendiceal mucinous adenocarcinoma
  • Appendiceal mucinous adenocarcinomas
  • Cystadenocarcinoma of the appendix
  • Cystadenocarcinomas of the appendix
  • Mucinous adenocarcinomas of the appendix

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