Intestinal Biopsy Uses and Pitfalls

In most cases of acute gastrointestinal (Gi) disease a ‘tissue diagnosis’ is not needed, and Gi tract biopsy is performed rarely. However, in many cases of chronic Gi disease a defin- itive diagnosis may depend on histopathological examination of biopies taken either surgically or endoscopically.

Endoscopy is more sensitive than exploratory surgery at visualising mucosal lesions that are within its reach, but endoscopic biopsies are sometimes too superficial to make a definitive diagnosis. Conversely surgical biopsy is indicated if a lesion in the intestine is beyond the reach of the endoscope, and solid tumours, intestinal lymphoma and lym- phangiectasia may be diagnosed more reliably with full-thickness biopsies. However the relative safety of endoscopy versus surgery still makes it the method of first choice for collecting Gi tract biopsies: the risk of dehiscence after surgical biopsy is significant, especially if the patient is malnourished and/or hypoproteinaemic, or the surgeon inex- perienced.

Best practice is to perform endoscopic biopsy before surgery is considered unless there is evidence that the disease is beyond the reach of the endoscope; the surgical option is only preferred initially if there is any possibility of other intraperitoneal disease or focal pathology. Biopsies should always be taken even in the absence of gross abnormalities, because microscopic changes may be present. Multiple biopsies (six or more) must be collected, because the size of the specimens, crush artifacts, and fragmentation can make interpretation difficult. thus the advantages of endoscopy to the patient and cli- ent are balanced by a number of drawbacks, and the client should always be warned that surgical biopsy might ultimately be required for definitive diagnosis. [...]