Appendix
Carcinoma
Mucinous neoplasms / (cyst)adenocarcinoma

Reviewer: Jaleh Mansouri, M.D. (see Authors page)

Revised: 29 February 2016, last major update August 2012

Copyright: (c) 2003-2016, PathologyOutlines.com, Inc.

PubMed Search: Mucinous neoplasms cyst adenocarcinoma appendix
Definition / General
  • Resembles ovarian tumor, 20% as common as cystadenoma
  • May present with pain due to distention of the viscus
  • Associated with pseudomyxoma peritonei, particularly if it ruptures
  • Gross Description
  • May have appearance of mucocele, cystadenoma
  • Often associated with pseudomyxoma peritonei
  • Micro Description
  • Malignant cells (destructive invasion of appendiceal wall, extensive full-thickness nuclear stratification, vesicular nuclei, marked nuclear membrane abnormalities, prominent nucleoli, frequent mitotic figures, complex papillary fronds, cribriform glandular spaces) in wall with desmoplastic stromal response (high-grade mucinous adenocarcinoma)
  • Some authors also classify as malignant if epithelial cells (which may appear benign) in peritoneal mucinous deposits (low-grade mucinous adenocarcinoma)
  • Term low-grade mucinous neoplasm/mucinous neoplasm of uncertain malignant potential may be used in cases of well-differentiated mucinous neoplasm without evidence of frank invasion (presence of undulating or broad front) or absence of tumor cells in mucin deposits
  • Micro Images

    Images hosted on other servers:

    Well-differentiated mucinous adenocarcinoma

    Molecular / Cytogenetics Description
  • 18q-
  • Positive Stains
  • CK18, CK20, CEA, CDX2, MUC2
  • Differential Diagnosis
  • Mucocele, (cyst)adenoma, tumors with mucinous differentiation from other primary sites
  • Additional References