mucinous adenocarcinomas

Digital case

 JRC:1597 : Cystic mucinous adenocarcinoma

Definition: Mucinous adenocarcinomas (MAs) of various origins may have a similar histologic appearance and frequently metastasize to distant sites.

Immunochemistry

 Homogenous CDX-2 and nuclear β-catenin expressions are commonly seen in lower GI tract MAs.
 Appendiceal MAs are usually heterogenously positive for CDX-2 and show cytoplasmic positivity for β-catenin.
 Unlike lower GI tract MAs, upper GI tract MAs are frequently positive for CK7 and MUC-6.
 As is the case in appendiceal MAs, the upper GI tract MAs may also be heterogenously positive for CDX-2.
 Breast MAs are positive for ER and WT-1, whereas gynecologic MAs are positive for PAX-8 and negative for WT-1.

See also

 Adenocarcinomas

References

 Determining the Site of Origin of Mucinous Adenocarcinoma: An Immunohistochemical Study of 175 Cases. Chu PG, Chung L, Weiss LM, Lau SK. Am J Surg Pathol. 2011 Aug 29. PMID: 21881489