Type:
Educational Exhibit
Keywords:
Abdomen, Liver, Ultrasound, CT, MR, Contrast agent-intravenous, Inflammation, Cirrhosis
Authors:
N. Sverzellati1, F. Milone2; 1Parma/IT, 2Parma, Catania/IT
DOI:
10.26044/ecr2019/C-2846
Background
Sarcoidosis is a multisystem inflammatory disease characterized by the presence of non-caseating granulomas that may develop in various organs.
Sarcoidosis affects both sex of all ages (more frequently women of 20 to 40 years of age) with a worldwide prevalence of 0,2 - 64 cases for 100.000 people.
Prevalence varies among different races and geographic areas,
with higher rates in African-Americans and Northern Europeans.
Etiology is still unclear,
but several studies demonstrated that Sarcoidosis might be the result of an exaggerated immune response to environmental antigens in genetically susceptible individuals.
The main factors involved in the pathogenesis of the disease are reported in the Fig.
1
The proposed mechanism of sarcoid granuloma formation is illustrated in Fig.
2
Lung and lymphoid system are the most commonly involved sites.
Extrathoracic manifestations (Fig.
3) occur in 40 - 50% of patients,
whose 50 – 80 % showed biopsy-proven liver involvement.
Isolated liver involvement may develop in 13% of cases.
CLINICAL FEATURES
Specific clinical features of the disease depend on the involved sites,
duration of the illness and activity of the granulomatous process.
Patients with hepatic Sarcoidosis are often asymptomatic or have symptoms not specifically related to liver involvement; more specific symptoms occur in 5 - 15% of patients (Fig.
4).
Liver function tests are abnormal in 35% of cases,
even if they are quite unspecific.
The most helpful laboratory tests in the diagnosis of Hepatic Sarcoidosis (HS) are:
-
Alkaline Phosphatase (ALP) --> from 5 to 10 times greater the upper limit of normal
-
Gamma–Glutamil–Transpeptidase (ϒ-GT) --> less reliable than the ALP level in predicting liver involvement
-
Angiotensin converting enzyme (ACE) --> higher levels are frequent in patients with active disease although normal levels do not exclude HS
-
Serum globulin level (GLB) --> high levels are common but quite unspecific
-
Anti-mitochondrial antibodies (AMA) --> normal level in patients with Sarcoidosis,
helpful in differential diagnosis with Primary Biliary Cirrhosis