**4. NAFLD and liver biopsy**

NAFLD is usually associated with metabolic risk factors such as metabolic syndrome, obesi‐

ty, diabetes mellitus, and dyslipidaemia.

162 Liver Biopsy – Indications, Procedures, Results

**Macrovesicularsteatosis**

Parenteral nutrition. Abetalipoproteinemia.

**Microvesicularstatosis**

Acutte fatty liver of pregnancy

**3. Epidemiology**

obesity[2].

Reye's syndrome.

HELLP syndrome

Excessive alcohol consumption. Hepatitis C (genotype 3) Wilson's disease. Lipodistrophy Starvation

**COMMON CAUSES OF SECONDARY HEPATIC STEATOSIS**

Medication (amiodarone, methotrexate, tamoxifen, corticosteroids)

Inborn errors of metabolism (LCAT deficiency, cholesterol ester storage disease, Wolman disease)

flammation, called NASH and progression to advanced fibrosis and cirrhosis.

NAFLD includes a constellation of histological findings that goes from steatosis, to necroin‐

NAFLD is becoming the leading cause of liver disease. One of the causes is the increasing of

The incidence of NAFLD has been evaluated in a few number of studies, it ranges from 31-86 cases/1000 person-year in Japan to 29 cases per 100000 person-year in England [3, 4].

The prevalence of NAFLD is increasing. Recent studies presented in the Digestive Diseases Week 2012 summarizes this increased prevalence over the last 20 years [5, 6]. Investigators report an increasing in obesity. This increase is followed by a rising in steatosis and NASH, the presence of steatosis among obese people has increased from 23% in the 80s, 43% in the

Medications (valproate, anti-retroviral medicines)

**Table 1.** Causes of secondary fat accumulation.

Liver biopsy remains the gold standard for characterizing liver histology in patients with NAFLD. However, it is expensive and carries some morbidity and very rare mortality risk. Thus, it should be performed in those who would benefit the most from diagnostic, thera‐ peutic guidance, and prognostic perspectives.

The last guideline for NAFLD management recommends liver biopsy [1]: in patients who are at risk to have steatohepatitis and advance fibrosis; theses patients could be identified by the presence of metabolic syndrome and NAFLD fibrosis score; and a liver biopsy should be considered in patients in whom other etiologies are suspected and cannot be excluded with‐ out a liver biopsy.

Liver biopsy allows confirming the diagnosis, evaluation and semiquantitation of necroin‐ flammatory lesions and fibrosis.

On the other hand, liver biopsy suffers from challenges. An adequate biopsy represents only 1/50000-1/65000 of the organ. Sampled area should be carefully chosen and sample length must be enough, a least 15mm. This size can reduce sample error. Finally, experienced path‐ ologist is important to haver a greater yield of findings.
