• All IHC stains will include a positive control tissue

• 95% of adenocarcinomas of colon, lung, breast, pancreas, biliary tract are CEA positive
• Renal cell, prostatic, hepatocellular, adrenocortical, and thyroid carcinomas as well as mesotheliomas are usually negative for CEA
  NOTE: When CEA is ordered, the monoclonal CEA will be automatically performed unless the polyclonal antibody is specifically requested. Polyclonal CEA also reacts with NCA (nonspecific cross reacting antigens) and BGP (biliary glycoproteins). It is the unique CEA/BGP expression that is useful in identifying hepatocellular carcinomas (see section on immunohistochemistry panels). Thus, if the hepatocellular carcinoma panel is requested, then both monoclonal and polyclonal CEA will be automatically performed.

Prepare a formalin-fixed, paraffin-embedded (FFPE) tissue block

Formalin-fixed, paraffin embedded (FFPE) tissue block

FFPE tissue section mounted on a charged, unstained slide

Ambient (preferred)

• Unlabeled/mislabeled block
• Insufficient tissue
• Slides broken beyond repair

Immunohistochemical staining and microscopic examination

If requested, an interpretive report will be provided

Specifications

• CEA is a family of HMW glycoproteins
• Expression of CEA by tumor is often proportional to degree of differentiation
• CEA also labels PMNs

Staining pattern

• Cytoplasmic and apical based staining