**Question:** Carcinoembryonic antigens (CEA) is except in which of the following conditions?

A. Congenital malformations
B. Chronic liver diseases
C. Inflammatory bowel diseases (IBD)
D. Gastric and colorectal cancers

**Core Concept:** Carcinoembryonic antigens (CEA) are a group of glycoproteins that are normally present in low concentrations in the fetal circulation and gastrointestinal tract mucosa. They are mostly involved in cell adhesion, differentiation, and migration. Elevated levels of CEA are commonly observed in various cancers, particularly colorectal cancers.

**Why the Correct Answer is Right:** CEA is an established marker for colorectal cancer and its elevated levels in the blood are associated with colorectal cancer. As a result, the correct answer (D) is right because CEA levels are usually increased in gastric and colorectal cancers.

**Why Each Wrong Option is Incorrect:**

A. Congenital malformations: CEA levels are not typically affected in congenital malformations.
B. Chronic liver diseases: Liver cirrhosis and other chronic liver diseases can alter the protein profile in the blood, but CEA is not a biomarker for liver diseases.
C. Inflammatory bowel diseases (IBD): Inflammatory bowel diseases like Crohn's disease and ulcerative colitis can cause elevated CEA levels, but they are not the primary cause of elevated CEA levels.

**Clinical Pearl:** Elevated CEA levels should be investigated further in patients with a known history of colorectal cancer, as it can serve as a marker for disease progression or recurrence. However, in patients with chronic liver disease or IBD, elevated CEA levels may be a result of inflammation rather than cancer. Hence, a comprehensive clinical evaluation is required when interpreting elevated CEA levels in these patients.