medical decision support medical decision support
Sign In

Aberrant Immunohistochemical Staining for CK7, CK20 and CDX2 in BRAF-Positive Colorectal Adenocarcinomas

Description

Colorectal adenocarcinomas with BRAF mutations may show aberrant staining with CK7, CK20 and CDX2. An unexpected phenotype may delay diagnosis or start an unnecessary investigation for another primary site. This can be particularly important when evaluating a biopsy from a remote site.


Typical phenotype for a colorectal adenocarcinoma:

(1) CK7 negative

(2) CK20 positive

(30 CDX2 positive

 

An adenocarcinoma with a BRAF mutation may be negative for CK20 and/or CDX2. Up to 13% of BRAF-positive tumors may be negative for both if the tumor shows microsatellite instability high (MSI-H).

 

An adenocarcinoma with BRAF mutation may also be positive for CK7 especially if the tumor is microsatellite stable (MSS).


To read more or access our algorithms and calculators, please log in or register.

Specialty

ICD-10