GI Path Online
An approach to evaluation of Small Intestinal Biopsy
Initial biopsy evaluation should
begin with a careful examination of the requisition to ascertain the
relevant clinical features of the patient and to ascertain the biopsy
Communication between the clinician and the pathologist is essential for evaluation of all small biopsy specimens.
small bowel biopsy :
2. Investigation of iron deficiency anaemia
3. Monitoring of coeliac disease
4. Diagnosis of neoplasia
5. Investigation of patients with diarrhoea particularly in patients where infection is suspected. Example: AIDS
6. In some cases enteroscopy may be performed to confirm NSAID induced ulceration or when there is bleeding from an unknown site.
Handling of the
The specimens are mounted on a filter paper, with the mucosa side up and placed in a fixative.
After the tissue is processed, it is embedded perpendicular to the mounting material.
Each specimen is serially or step sectioned in atleast three levels.
-Signs and symptoms ;
-Site of the biopsy ;
-Endoscopic findings ;
-Previous medical and surgical history ;
-History of intake of drugs or alcohol ;
-History of immunosuppression;
-Findings of previous biopsies.
obtaining biopsy from the small intestine:
(1) Suction biopsies (2) Endoscopic biopsies :
Formerly, suction biopsies were taken from the jejunum.
Crosby suction capsules were used.
Biopsies were larger in size and were more easily orientated in the laboratory.
Now endoscopic mucosal biopsies have replaced suction biopsies because of its convenience for the patient and its speed.
Endoscopic biopsy specimens are smaller and since it is performed under direct vision more specimen can be obtained.
Normal histology of the
Proximal duodenum may contain islands of typical antral type mucosa and 'transitional epithelium' consisting of cells showing both antral and intestinal features.
Villi are shorter and broader than jejunum.
Submucosal Brunner's glands are present (contains neutral-PAS positive mucin in contrast to alcian blue positive acid sialomucin of goblet cells).
Ileum contains more number of goblet cells and villi are shorter and more fingerlike in shape.
Peyer's patches are more prominent in the ileum.
The report should include the following information:
- Number and site of the biopsies
- Are the biopsies normal or abnormal?
- Villous height and architecture -
Identification of four normal villi in a row suggest that the villous architeture of the entire specimen is normal.
The villous architecture may be normal, broad or blunted.
Villous height is shortened : Partial villous atrophy (mild, moderate , severe) and subtotal villous atrophy.
abnormal small bowel architecture -
Whipples disease; Parasitic infestation; Intestinal lymphangiectasia ; Immunodeficiency syndrome; Enteropathy associated T cell lymphoma; Abetalipoproteinemia ; Eosinophilic gastroenteritis.
-Villous height : crypt length ratio -
The ratio of villous height to crypt length in the normal small intestine varies from about 3:1 to 5:1.
-Presence of crypt hyperplasia -
Characterized by increase in the length of crypts, a reduction in the normal villous : crypt ratio and increased number of mitotic figures due to extension of the proliferative compartment from the crypt bases along the length of the crypt .
-Surface enterocytes -
Normal, flattened or damaged.
-Brush borders -
Preserved or lost
-Intraepithelial lymphocyte count -
Normal count is usually less than 30 per 100 surface epithelial cells.
IEL count is more than 40 per 100 epithelial cells in celiac disease.
-Foveolar metaplasia -
In chronic duodenitis.
Giardia ; Cryptosporidium ; Microsporidium ; Mycobacterium avium intracellulare.
Presence of benign or malignant tumour.
Example: Adenoma or carcinoma; Carcinoid ; Lymphoma
Special stains commonly performed :
1.PAS stain: Demonstrate macrophages in Whipple's disease, highlight fungi , foveolar metaplasia in chronic duodenitis and integrity of the brush border.
2.Wade Fite or Ziehl Neelson : Mycobacteria
3.Giemsa or mucicarmine: Microorganisms like Cryptosporidium and Microsporidium.
4.Trichrome stain: Confirm collagen deposits in ischaemia or collagenous sprue.
hematoxylin counterstain in trichrome technique:
1. CD34 : for stromal tumours
2. S100 protein: neural differentiation in stromal tumour
3. SMA and desmin : demonstrate myogenic differentiation in stromal tumour.
4. Lymphoid markers : Lymphoma.
5. NSE, Chromogranin : Neuroendocrine differentiation of tumour.
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