Neonatal Liver Biopsy

Dr Claire Bowen

Consultant Paediatric Pathologist

Topics Covered

• Neonatal jaundice• Indications for biopsy• Handling of biopsy in the laboratory• Histological assessment of the liver biopsy• Patterns of liver disease with examples

– Biliary atresia– A1AT– Cystic fibrosis– Neonatal hepatitis– Metabolic

Neonatal Jaundice• Common

– 60% term and 80% of preterm babies develop jaundice in first week of life

– 10% breast fed babies still jaundice at 1 month• Usually harmless

– High concentrations of conjugated hyperbilirubinaemia can cause permanent brain damage (kernicterus)

• Prolonged jaundice can be a sign of underling serious liver disease (conjugated bilirubinaemia >25 umol/L)

• Early recognition and prompt treatment essential– Phototherapy– Kasai portoenterostomy– Metabolic screening– Transplant

Indications

Biopsy indicated• Conjugated

hyperbilirubinaemia– Jaundice persisting

beyond 2 weeks (3 weeks in preterm babies)

– Dark urine– Pale stools

• Total parenteral nutrition in the context of intestinal failure

• Assessment of rejection post-transplant

• Tumour

Biopsy not indicated• Unconjugated

hyperbilirubinaemia – Physiological– Sepsis– Haemolysis

• Liver failure– Coagulopathic– Limited contribution to

aetiology– Usually see explanted

liver

Handling

• Procedure risk - general anaesthetic, bleeding

• Need maximum amount of information from biopsy

• Light microscopy

• Snap frozen tissue for metabolic cases

• Electron microscopy for storage disorders

• Dry tissue for copper

H&E• Number and size of tissue cores• Portal tracts

– Number– Presence/absence of bile ducts– Bile duct proliferation– Inflammation– Fibrosis

• Parenchyma– Giant cell transformation– Rosetting of hepatocytes– Haematopoiesis– Storage cells

• Central veins– Vascular flow abnormalites– Inflammation in rejection

Special stains

• Connective tissue stains to assess fibrosis– EVG – mature fibrosis/pericellular fibrosis

– Reticulin – cell plates, acute collapse

– Trichrome – tends to overestimate fibrosis

• Orcein - Copper associated protein and Hep B

• Perls to assess iron

• PAS/DPAS – glycogen, storage cells and Alpha-1-Antitrypsin globules

Van Gieson

Reticulin

Orcein

Perls

DPAS

Histological patterns

1) Biliary Features

• Fibrosis– Fibrous portal tract expansion– Bridging fibrosis– Lobular pattern of cirrhosis

• Ductular proliferation• Ductular bile plugging• Periportal copper-associated protein• Variable giant cell change• Haematopoiesis

Differential diagnosis

• Extrahepatic biliary atresia

• Alpha-1-antitrypsin (mimic)

• Total parenteral nutrition

• Cystic fibrosis – eosinophilic secretions in bile duct and fatty change

Biliary Atresia

• Rare - 1 in 17000 in UK• Presents in first few weeks• 50 cases a year with normal antenatal scans• 20% other anomalies (cardiac, polysplenia)• Lumen of biliary tree obliterated with

obstruction to bile flow• Progressive liver damage – cirrhosis• 5 categories of postulated aetiology –>

Inflammatory, Developmental, Vascular, Environmental and Viral

Alpha-1 Antitrypsin

• Defective A1AT protein• Defective production of A1AT leading to

decreased A1AT activity in the blood and lungs• Deposition of excessive abnormal A1AT protein in

liver cells. • Mimics – Can see biliary pattern or giant cell

pattern• PAS positive globules within hepatocytes – not

identified in first 3 months• Immuno for A1AT

Cystic Fibrosis

• Liver disease 5% in CF patients

• Fibrosis

• Cholestatsis

• Fatty change

• Biliary features

• Mucin in bile ducts characteristic but not always seen

2) Neonatal / giant cell hepatitis

• Largely normal portal tracts• Hepatocyte disarray and collapse• Florid giant cell change• Rosetting of hepatocytes• Cholestasis• Extramedullary haematopoiesis• May see storage cells• Not usually fibrotic

Differential diagnosis

• Idiopathic with spontaneous recovery• Infection• Metabolic• Storage• A1AT

3) Paucity of bile ducts

• Bile duct proper lacking

• Need at least 10 portal tracts (1 in 10 miss bile duct normally)

• Abberent periportal cytokeratin 7 expression– Normally stains biliary epithelium– Stains periportal hepatocytes where there is

duct loss

Differential diagnosis

• Syndromic– Alagilles syndrome

• Non-syndromic– CMV infection– A1AT– Cystic fibrosis– Chronic rejection

Alagille syndrome

• Characteristic facial features – triangular face• Heart problems• Bile ducts seen in early biopsies• Progressive bile duct loss/absence• Fibrosis• Abberant Cytokeratin 7 staining in periportal

hepatocytes

Early features

Late Features

4) Bland cholestasis

• Canalicular cholestasis

• No ductular reaction or bile plugging

• Minimal parenchymal changes

• +/- Fibrosis

Pitfalls in children

• Copper-associated protein present in babies up to 3 months (periportal)

• Small amounts of periportal iron present at birth

• Fat not generally seen, metabolic conditions should be considered

• Hepatocyte plates 2 cells thick until 5/6 years

• Erythropoiesis stops approx. 36 weeks gestation

Neonatal Haemochromatosis• Severe form of iron

overload• Starts to accumulate in

utero - can cause fetal death

• Liver failure• Massive necrosis –

collapse• Iron +++• Usually diagnosed on lip

biopsy – iron storage in salivary glands