Colorectal biopsy

Specimen:

Endoscopic biopsy or surgical biopsy. 

Biopsies for Hirschsprung's disease require at least the submucosa to be included. 

Blood should also be collect for CEA and CA 19.9 (see Tumour markers and Carcinoembryonic Ag) if carcinoma is suspected.

Method:

Fresh tissue: for frozen section and evaluation of Hirschsprung's disease, molecular genetics (tumours including lymphoma).

Immediate examination of fresh tissue for trophozoites of Entamoeba histolytica, if amoebiasis is suspected. 

Fixed tissue: for light microscopy, Immunohistochemistry, Electron microscopy (special fixative). 

Application:

Diagnosis of suspected acute or chronic Inflammatory bowel disease; chronic watery diarrhoea; infective colitis.

Diagnosis of localised lesions such as ulcers, polyps and stenotic areas; surveillance for dysplasia in chronic colitis; tumour type, grade and stage. 

Identification of amyloid deposits. 

Diagnosis of Hirschsprung's disease and mapping the extent of aganglionic segment.

Interpretation:

Report by pathologist identifies disease process, including tumour type, grade and stage. 

Motile trophozoites containing ingested red cells are diagnostic of Entamoeba histolytica infection. 

The diagnosis of Schistosomiasis may be made by finding characteristic ova/parasites in a rectal biopsy.

Reference:

Montgomery, E. Biopsy interpretation of Gastrointestinal tract mucosa. Vol 1 and 2. 2012 (2nd Ed) Lippincott, Williams and Wilkins.