Liver granuloma

Liver granulomas can be caused by various causes and usually occur asymptomatically.

However, diseases that cause granuloma formation may be accompanied by extrahepatic symptoms and / or lead to liver inflammation, fibrosis and portal hypertension. Diagnosis is based on liver biopsy results, but a biopsy is necessary only if there is a suspicion of a disease that can be treated (eg, an infection) or other liver diseases. Treatment of granulomas of the liver is determined by the underlying disease.

The liver granulomas themselves may not have much significance, but are often a manifestation of a clinically significant disease. The term "granulomatous hepatitis" is often used to describe status, but this disorder is not a true hepatitis, and the presence of granulomas does not imply hepatocellular inflammation.

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Causes of Liver Granuloma

Granuloma is a limited accumulation of chronic inflammatory cells along with epithelioid and giant multinucleated cells. There may be caseous necrosis or foreign body tissue (for example, eggs with schistosomiasis). Most granulomas are in the parenchyma, but granulomas can be observed in liver triads with primary biliary cirrhosis.

Mechanisms for the formation of granulomas are not completely uncovered. Granulomas can be formed in response to exogenous or endogenous stimuli, while immune mechanisms are involved.

Liver granulomas have many causes, more often they are medications and systemic diseases (often infections), but not primary liver damage. Infection is very important to diagnose, since they require specific treatment. Worldwide, the main infectious causes of granuloma formation are tuberculosis and schistosomiasis; in more rare cases, the granuloma is formed during a viral infection. Sarcoidosis is the main

Clinicians distinguish the following reasons for the formation of granulomas of the liver:

• Drugs (for example, allopurinol, phenylbutazone, quinidine, sulfonamides)
• Infections
  • Bacterial (actinomycosis, brucellosis, "cat scratch" disease, syphilis, tuberculosis and other mycobacteria, tularemia)
  • Fungal (blastomycosis, cryptococcosis, histoplasmosis)
  • Parasitic (schistosomiasis, toxoplasmosis, visceral larva of the nematode)
  • Viral (cytomegalovirus, infectious mononucleosis, fever Ku)
• Diseases of the liver (primary biliary cirrhosis)
• Systemic diseases (Hodgkin's lymphoma, rheumatic polymyalgia and other connective tissue diseases, sarcoidosis)

The most common reasons are:

• The cause of non-infectious nature; liver damage is observed in about two-thirds of patients and is sometimes dominant in the clinical picture.
• Granulomas are less characteristic of primary liver diseases, of which primary biliary cirrhosis is the only important cause. Small granulomas sometimes develop with other liver diseases, but they do not have much clinical significance.
• Idiopathic granulomatous hepatitis is a rare syndrome that includes liver granulomas, recurring fever, myalgia, fatigue and other common symptoms that recur periodically for years. Some authors believe that this is a variant of sarcoidosis.
• Liver granulomas rarely break the hepatocellular function. However, if granulomas are part of a more general inflammatory response involving the liver (eg, reaction to a drug, infectious mononucleosis), hepatocellular dysfunction appears. Sometimes inflammation causes progressive liver fibrosis and portal hypertension, which is usually observed with schistosomiasis and sometimes with extensive infiltration in sarcoidosis.

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Symptoms of liver granulomas

Directly granulomas occur, as a rule, asymptomatic; even significant infiltration usually causes only minor hepatomegaly and little jaundice or its absence. Symptoms, if they occur, reflect the underlying cause (eg, systemic signs of infection, hepatosplenomegaly in schistosomiasis).

Diagnosis of liver granulomas

If there is a suspicion of liver granulomas, functional liver tests are performed, but their results are nonspecific and rarely help in diagnosis. The level of alkaline phosphatase (and gamma-glutamyl transferase) often increases slightly, but in some cases it is high. The results of other studies may be within the normal range or show abnormalities reflecting additional liver damage (eg, extensive inflammation due to reaction to the drug). Instrumental studies such as ultrasound, CT or MRI are generally not diagnostic, but they can reveal calcification (if the process is chronic) or fill defects, especially when merging lesions.

Diagnosis is based on liver biopsy. However, a biopsy is usually performed only for the diagnosis of a treatable disease (eg, infection), or for differential diagnosis with non-granulomatous lesions (eg, chronic viral hepatitis). Biopsy sometimes reveals the presence of a specific cause (eg, eggs with schistosomiasis, caseous decay in tuberculosis, fungal infection). At the same time, other studies are often necessary (for example, crop culture, skin tests, laboratory and radiographic studies, other tissue samples).

In patients with common or other symptoms suggestive of an infection (eg, fever of unknown etiology), specific studies should be used to increase the diagnostic value of the biopsy for infection verification (for example, a portion of fresh biopsy material is sent for culture and special coloring on acid-fast bacilli, fungi and other organisms). Quite often, the reason is not established.

[11], [12], [13]

Treatment of granulomas of the liver

Liver granulomas caused by drugs or infection completely regress after treatment. Granulomas in sarcoidosis may disappear spontaneously or persist for years, usually without the development of clinically significant liver disease. Progressive fibrosis and portal hypertension are rare (sarcoidosis of the liver). For schistosomiasis is characterized by progressive portal sclerosis (pipestem fibrosis, fibrosis of Simmers); the liver function is usually preserved, but splenomegaly is noted and bleeding from varicose veins can develop.

Treatment is directed to the main cause. If the cause is unknown, treatment is usually abstained and continues to periodically check liver function (functional liver tests). However, if signs of tuberculosis (eg, prolonged fever) appear and the condition worsens, the onset of empirical antituberculous therapy may be justified. With progressive sarcoidosis of the liver, the use of glucocorticoids may be effective, although it is not known whether they can prevent the development of liver fibrosis. However, the use of glucocorticoids is not indicated in most patients with sarcoidosis, and their use is possible only if tuberculosis and other infections are excluded completely.