My son, 51, has been told he has fatty tissue around his liver and a biopsy is needed. Exactly what is the procedure for a liver biopsy?

Cynthia

A liver biopsy is often done as a follow-up to blood tests or imaging tests (ultrasound, CT scan, MRI) indicating possible liver abnormalities. The procedure, in which doctors remove a tiny piece of the liver for laboratory analysis, may be done in one of three ways.

The oldest method simply involves locating the position of the liver on the right side of the abdomen, giving the patient local anesthesia and then placing a needle directly into the liver through the skin between two ribs on the right side. This procedure takes only a few minutes and is safe if done by an experienced doctor. If a patient is anxious, IV sedatives may be given before this procedure.

A newer method of liver biopsy is done using laparoscopy, which involves making a small incision in the abdomen and inserting a flexible tube through which doctors can manipulate a tiny camera and surgical equipment. Although this takes longer than needle biopsy, the laparoscopic camera enables doctors to actually view the liver and remove tissue samples only from those areas that look abnormal.

The latest method of liver biopsy appears to combine the best of the other two strategies. Called "guided biopsy," it uses high-tech imaging (either by ultrasound or CT scan) to help doctors pinpoint abnormal areas of the liver to target with the standard needle biopsy. Unlike a laparoscopic biopsy, it requires no incisions and, unlike regular needle biopsy, it helps to spare healthy liver tissue from the damage that may be caused by random sampling.

The choice of biopsy method usually depends on a patient's symptoms, as well as what type of biopsy the hospital staff is familiar with performing. After a piece of liver is removed through biopsy, the tissue is sent to a specialist called a pathologist to be analyzed under a microscope. The appearance of the liver cells can provide doctors with very specific information about what is wrong with the liver. For example, in fatty liver disease, fat accumulates in the liver cells, and they also appear inflamed.