Duodenal biopsy

Duodenal biopsy (DUB) — is the taking of samples of the mucous membrane of the initial part of the small intestine during an endoscopic examination (EGD). This manipulation is key for the diagnosis of diseases accompanied by impaired absorption of nutrients (malabsorption), as well as for the differential diagnosis of tumors and inflammatory processes.

Research objective: The main task is to morphologically assess the condition of the intestinal villi. This is the "gold standard" for confirming celiac disease (gluten intolerance), as well as a method for excluding parasitic invasions, specific infections, and oncological diseases.

What does the pathologist evaluate:

• The structure of villi and crypts: assessment of their height and shape (in pathologies, the villi may become smooth or disappear).

• Interepithelial lymphocytes: counting their number for diagnosing celiac disease (according to the Marsh classification).

• Presence of microorganisms: searching for Giardia, Whipple's disease pathogens, or signs of fungal infection.

• Cellular atypia: detection of precancerous changes or malignant tumors (adenocarcinomas, lymphomas).

• Degree of inflammation: assessment of the severity of duodenitis and the presence of erosions.

Clinical significance: Biopsy results allow the gastroenterologist to determine the cause of chronic diarrhea, unexplained anemia, and vitamin deficiencies. Accurate diagnosis of celiac disease by biopsy is critical because it requires the patient to follow a strict diet for life.

When is it prescribed:

• suspected celiac disease (gluten enteropathy);

• chronic diarrhea and weight loss;

• iron deficiency anemia, the cause of which has not been established;

• detection of polyps, ulcers, or thickening of the duodenal folds during endoscopy;

• suspected Whipple's disease or giardiasis.