Biopsy of the intestine
Intestinal biopsies are frequent and, in contrast to many other biopsy procedures, are almost exclusively performed as part of endoscopic examinations. There are two ways to look at the intestine, within the scope of gastroscopy and colonoscopy. In gastroscopy, the examination is performed through the mouth and extends to the beginnings of the small intestine at most.
In a colonoscopy, the entire large intestine and in some cases the end of the last section of the small intestine can be examined through the anus. In order to be able to observe the very long and very tortuous small intestine completely, a capsule endoscopy is necessary, but biopsies cannot be performed. In a normal colonoscopy, the biopsy sample can be obtained using the endoscope with forceps.
Especially small polyps and ulcers of the intestinal wall are removed. Based on the samples of mucous membrane tissue from the inside of the colon, inflammations, benign and malignant tumours can be differentiated, as well as other intestinal diseases. The biopsy in the intestine is usually not painful.
During the endoscopic examination one is normally sedated and asleep. Occasionally small amounts of blood may be found in the stool afterwards. An infection of the biopsy site is a very rare complication.
A biopsy in the brain is only performed after exact previous radiological examinations. If changes are found in a CT or MRI examination of the brain, it must be assessed how fast the structures are growing. If there is no time left and the change in the brain is already symptomatic, a biopsy must be performed in order to start therapy as soon as possible.
The cause of such altered structures in brain tissue can be inflammatory lesions as well as different types of brain tumours, which must be treated differently. The biopsy in the brain must be planned exactly so that healthy tissue is not endangered under any circumstances and consequential damage does not occur. The location of the brain structure to be examined is precisely determined by means of several imaging techniques.
Subsequently, the skull is opened during an operation and the biopsy is performed with a hollow needle with millimetre precision and accuracy. The tissue sample can already be analysed in the operating theatre.