Articles on Medical Diseases and Conditions

Tag: Liver Biopsy

  • Metastatic Carcinoma

    Metastatic tumor to the liver may be completely occult or may produce a clinical or laboratory picture compatible with hepatomegaly of unknown origin; normal liver with elevated ALP levels simulating bone disease; active cirrhosis; or obstructive jaundice. The liver is a frequent target for metastases, some of the most common primary sites being lung, breast, prostate, and both the upper and lower GI tract. Earlier reports frequently stated that metastases to a cirrhotic liver were rare, but later studies have disproved this. By far the most frequently noted abnormality is hepatic enlargement. About 25% of patients with metastatic tumor to the liver become jaundiced, and another 25% have elevated bilirubin levels (usually with the conjugated fraction predominating) without clinically evident jaundice. Occasionally patients develop jaundice with relatively little hepatic tissue replacement. In about 10% of patients the bilirubin levels are high enough (>10 mg/100 ml; 170 µmol/L) to simulate obstruction of the common bile duct. A significant minority of patients with tumor in the liver may have physical findings compatible with portal hypertension or cirrhosis.

    In 50%-60% of patients with metastatic carcinoma to the liver the serum bilirubin level is normal, whereas ALP levels are elevated in about 80% of patients (range, 42%-100%) and GGT in about 88% (45%-100%). Therefore, ALP or GGT levels are frequently elevated in nonjaundiced patients with liver metastases, and ALP elevation may occur in some instances when only a relatively few tumor nodules are present. The most typical pattern for metastatic carcinoma to the liver is a normal bilirubin level, normal AST level, and elevated GGT and/or ALP level of liver origin. If the serum bilirubin level is elevated, the typical metastatic tumor pattern becomes less typical or is obscured, because many of these patients develop mildly abnormal AST values suggestive of mild acute hepatocellular damage in addition to the elevated ALP level. Diagnosis is much more difficult when liver function test results other than ALP or GGT are abnormal since these other test results can be elevated (at least temporarily) from any of a considerable variety of etiologies. Unfortunately, only about one third (or less) of metastatic tumor cases have elevated ALP or GGT levels and normal AST levels. Finally, whether or not a patient has elevated bilirubin, ALP or GGT may be elevated due to nonhepatic etiology (i.e., phenytoin therapy, sepsis). Some investigators report that carcinoembryonic antigen (CEA) is more sensitive in detecting colon cancer metastasis to the liver than is ALP, but this is a minority opinion.

    As mentioned previously, a liver scan (radionuclide, CT, or ultrasound) is very useful. Liver biopsy is usually necessary for definite diagnosis. Biopsy sometimes may demonstrate tumor when other tests are normal, equivocal, or conflicting, or when the biopsy is performed because of some other preliminary diagnosis.

  • Liver Biopsy

    This procedure has been greatly simplified, and its morbidity and mortality markedly reduced, by the introduction of small-caliber biopsy needles such as the Menghini. Nevertheless, there is a small but definite risk. Relative contraindications to biopsy include a PT in the anticoagulant range or a platelet count less than 50,000/mm3. Liver biopsy is especially useful in the following circumstances:

    1. To differentiate among the many etiologies of liver function test abnormality when the clinical picture and laboratory test pattern are not diagnostic. This most often happens when the AST level is less than 10 or 20 times the upper reference limit and the ALP level is less than 3 times the upper limit. In cases of possible obstructive jaundice, extrahepatic obstruction should be ruled out first by some modality such as ultrasound.
    2. To prove the diagnosis of metastatic or primary hepatic carcinoma in a patient who would otherwise be operable or who does not have a known primary lesion (in a patient with an inoperable known primary lesion, such a procedure would be academic).
    3. In hepatomegaly of unknown origin whose etiology cannot be determined otherwise.
    4. In a relatively few selected patients who have systemic diseases affecting the liver, such as miliary tuberculosis, in whom the diagnosis cannot be established by other means.

    A discussion of liver biopsy should be concluded with a few words of caution. Two disadvantages are soon recognized by anyone who deals with a large number of liver specimens. First, the procedure is a needle biopsy, which means that a very small fragment of tissue, often partially destroyed, is taken in a random sample manner from a large organ. Localized disease is easily missed. Detection rate of liver metastases is about 50%-70% with blind biopsy and about 85% (range, 67%-96%) using ultrasound guidance. Second, many diseases produce nonspecific changes that may be spotty, may be healing, or may be minimal. Even with an autopsy specimen it may be difficult to make a definite diagnosis in many situations, including the etiology of many cases of cirrhosis. The pathologist should be supplied with the pertinent history, physical findings, and laboratory data; sometimes these have as much value for interpretation of the microscopic findings as the histologic changes themselves.

    In summary, liver biopsy is often indicated in difficult cases but do not expect it to be infallible or even invariably helpful. The best time for biopsy is as early as possible after onset of symptoms. The longer that biopsy is delayed, the more chance that diagnostic features of the acute phase have disappeared or are obscured by transition to healing.