BENIGN FOCAL LESIONS IN LIVER

DR.SAJITH .S

CELL OF ORIGIN

• Hepatocellular.• Cholangiocellular.• Mesenchymal.

Hepatocellular origin

• Adenoma• Focal Nodular Hyperplasia ( FNH )• Hepatocellular Nodules in Cirrhosis.• Nodular Regenerative Hyperplasia ( NRH ).

Cholangiocellular origin

• Hepatic Cyst.• Biliary Hamartomas.• Peribiliary Cyst.• Biliary adenoma.• Biliary Cystadenoma.• Caroli Disease.• Biliary Papillomatosis.

Mesenchymal origin

• Cavernous Hemangioma.• Hemangioendothelioma( adult, infantile )• Focal Fat.• Angiomyolipoma.• Lipoma.• Peliosis Hepatis.• Paraganglioma.

Cavernous hemangioma

• Most common primary liver tumor.

• All age groups. • females >> males.• Size less than 1 cm to 30

cm (giant hemangioma).

Clinical presentation

• No signs and symptoms.• When tumor exceeds 4 cm ,abdominal

pain/discomfort or a palpable mass.• Rupture occurs rarely.

characteristics

• Usually solitary.• Borders are clear.• Not encapsulated.• Various degenerative changes are seen in its

centre.– Old and new thrombus formation.– Necrosis, scarring, hemorrhage & calcification.

usg

• Focal, homogenous, hypo vascular and hyperechoic lesions.

ct

• Hypodense area with same density of aorta.• Arterial phase-peripheral enhancement is seen

first, followed by gradual filling towards the centre.

• Equilibrium phase-prolonged enhancement.• In precontrast, arterial, equilibrium phases

tumor density is similar to that of aorta.

mri• Hypointense on T1.• Hyperintense on T2.• In T2 signal intensity is higher than that of

spleen.

Focal nodular hyperplasia

• Second common benign lesion.• Female >> male. 8:1• Reactive change to abnormal circulation.• Well defined lesion characterized by a central

fibrous scar.

Clinical presentation

• Usually asymptomatic.• Epigastric pain and hepatomegaly are seen

frequently.

characteristics

• Well-demarcated.• Solitary mass without a capsule.• Often located beneath the surface of liver.• In central scar - feeding arteries, draining veins

connecting to hepatic vein.• Necrosis and hemorrhage usually not seen.

usg• Iso to hypoechoic.• Colour doppler-central vascularity.

ct

• Homogenous hypodense mass with a central scar showing more marked hypodense.

• Arterial phase- brisk homogenous enhancement.• Portal phase-early wash out.• Delayed phase-barely visible.• If vessels radiating from central scar to the

periphery of the tumor is visualized , a near definite diagnosis of FNH.

mri

• Iso - hypointense on T1.• Hyper - isointense on

T2.• Central scar– Hypointense on T1.– Hyperintense on T2.

Adenoma

• Rare benign tumor in younger age group compared to FNH.

• Solitary (80%).• Females (90%).• Predisposing factors-oral contraceptives,

anabolic steroids and glycogen storage disease.

Clinical presentation

• Abdominal mass.• Recurrent abdominal pain.• Acute abdomen (tumor rupture).

Characteristics

• Clear border• No capsule (fibrous capsule in some cases)• Core - bleeding, necrosis, scar tissue• Contains-fat & glycogen• Neither portal vein nor bile ducts

usg

• May be hypo, iso, hyperechoic.• Typically heterogenous with areas of fluid

component.• Variable degrees of hemorrhage, necrosis &

fat.• Calcification rare.

ct

• Hypodense mass.• Hyper attenuation areas in

case of ruptured.• Area of necrotic foci and

scar tissue – hypodense areas

• Calcification is rare.• Moderate tumor

enhancement in atrerial phase.

mri

• Hyper to isointense on T1• Hypo to hyperintense on T2• Hemorrhagic tumor hyperintense on T1 & T2

Hepatocellular nodules in cirrhosis

• Classified as regenerative nodule, dysplastic nodule.

• Regenerative nodules:– USG and CT –too small to detect.–When regenerative nodules contain iron, they are

termed siderotic nodules.– Siderotic nodules- hyperdense on UECT and

hypointense on both T1 and T2.

• Dysplastic nodules :– Rarely diagnosed by USG or CT–MRI- Isointense with hyperintense foci on T1– Hypo on T2.(opposite to HCC).

angiomyolipoma

• Rare benign tumor.• Composed of mature fat, blood vessels and

smooth muscle cells.• It is not capsulated.• Tuberous sclerosis is a known association of

hepatic angiomyolipoma.

usg

• Circumscribed hyperechoic lesion.

ct

• Solid mass containing markedly hypodense area.

• Arterial phase- partially enhancement often with visualization of large central vessels.

mri

• Hyperintense on both T1 & T2.• Decreased intensity with fat suppression.

T1 Fat sup T1

Hepatic cyst

• Single/multiple.• Lined by single layer of cuboidal epithelium.• Older adults

• Clinical presentation– Asymptomatic– Compressive symptoms (massive).

usg

• Fine cystic lesion with partial or complete septa are often visualized.

• In case of complications – debris, thickened septa and complex internal fluid.

ct• Smooth rimmed

hypodense mass.• HU value near zero.• No enhancement at all

on CECT.

mri

• Hypointense on T1.• Extremely hypointense on T2.

Infantile hemangioendothelioma

• Common infant benign lesion.• Resembles capillary hemangioma seen in

infantile skin and mucosa.• With in 6 months of birth.• Solitary mass but may be multifocal.• Typically large (1-20 cm).

Clinical presentation

• Hepatomegaly.• Abdominal mass.• congestive heart failure.• Bleeding,anemia,thrombocytopenia.• Cutaneous hemangioma.• Occasionally jaundice.

ct• Hypodense area.• 16%- calcification and hemorrhage.• CECT – similar to that of cavernous

hemangiomas.• MRI-Resemble those of hepatic hemangioma.

Biliary cystadenoma

• Multi locular cystic liver mass.• Originates from bile duct.• Usually right hepatic lobe.• Adults, Females >> males.• Malignant transformation to cystadenocarcinoma

is not uncommon.

• Clincal presentation– Chronic abdominal pain.

usg

• Hypoechoic cystic lesion .• Intracystic soft tissue components may be

present.• Focal calcification can occur.

ct• UECT – well defined hypodense lesion.• Wall and internal septations are often

visualized (differentiate from simple cyst).• CECT – cyst wall and soft tissue component

typically enhance.

Hepatic abscess

• Commonly – pyogenic,amebic and fungal.• Via – portal vein, hepatic artery or bile duct.• Solitary or multiple.

ct

• Pyogenic – double structured hypodense area.– CECT : double target sign.( arterial phase)• Thick ring like stain (portal and venous phase)

• Amoebic – CECT- enhanced mural structure with hypodense area at its lateral side owing to the presence of oedema.

• Fungal – CECT – faint ring like enhancement (arterial phase )– Hypodense (venous phase).

Hydatid cyst

• All age group.• Caused by larva stage of adult tape worm.

Ct and mri

• Thick walled cystic lesions with internal round periphery daughter cysts.

• Attenuation and signal intensity in mother cyst is more than daughter cyst.

Common Benign lesions in liver

Common benign lesions

Scar Caps Ca++ Fat Blood Cystic

Hemangioma + + +FNH + +Adenoma + + +Abscess +Cystadenoma + +Angiomyolipoma +

benign lesions

• Hyper vascular– Hemangioma.– Adenoma.– FNH.

• Scar– FNH– Hemangioma