This document summarizes various malignant focal liver lesions including hepatocellular carcinoma (HCC), fibrolamellar carcinoma (FLC), hepatoblastoma, intrahepatic cholangiocarcinoma (ICCA), and metastases. It describes the epidemiology, risk factors, imaging appearance and characteristics of each lesion on ultrasound, CT and MRI. Common imaging findings include arterial phase enhancement on CT/MRI for HCC and FLC due to their hypervascular nature. Hepatoblastoma often demonstrates intralesional hemorrhage, necrosis and calcifications. ICCA typically shows delayed central enhancement on CT. Metastases exhibit a variety of appearances depending on the primary tumor and degree of necrosis.

1. Malignant
focal
lesions of
the liver
Sanal kumar

2. Malignant focal lesions of the liver
Hepatocellular carcinoma(HCC)
Fibrolamellar carcinoma (FLC)
Intrahepatic cholangiocarcinoma
Hepatoblastoma
Metastases
Angiosarcoma
Lymphoma
Epithelial hemangioendothelioma

3. Hepatocellular Carcinoma (HCC)
HCC is the most common malignant neoplasm of the liver worldwide.
HCC is the fifth most common cancer in the world and is the third
most common cause of cancer-related death (after lung and stomach
cancer).
HCC are typically diagnosed in adults in late middle age or elderly.
The tumour is however also identified in the paediatric population
where it is the second most common primary liver tumour
after hepatoblastoma.

4. HBV infection: 10%
HCV infection: 30%
Alcoholism: 8%
Biliary cirrhosis: 5%
Haemochromatosis: 21%
5 year cumulative risk
Congenital biliary atresia
Alpha-1 antitrypsin deficiency
Type 1 glycogen storage disease
Wilson disease
Any patient with chronic liver
disease is at risk for the
development of HCC and 80% of
HCCs occur in cirrhotic livers.

5. Alpha-fetoprotein
(AFP) levels are
elevated in 50-75% of
cases

6. Pathologically, HCC occurs in the following three forms:
oSolitary tumor
oMultiple nodules
oDiffuse infiltration
There is a propensity toward venous invasion. The portal vein is
involved in 30% to 60% of cases and more often than the hepatic
venous system.

7. Ultrasound
The sonographic appearance of HCC is varied.
These lesions are frequently hyperechoic, particularly if there is
fatty change or marked sinusoidal dilatation.
Small HCCs (<3 cm) often appear hypoechoic and are associated
with posterior acoustic enhancement, and tumors larger than 3 cm
more often have a mosaic or mixed pattern.
With time and increasing size, the masses tend to become more
complex and inhomogeneous as a result of necrosis and fibrosis.

9. Ultrasound is also capable of demonstrating the capsule in
encapsulated HCC, which appears as a thin, hypoechoic band.
Sonography, in conjunction with color and duplex Doppler, can
diagnose tumor thrombus in the portal and hepatic veins as well as
the inferior vena cava. The portal vein is involved in 30% to 60% of
cases and more often than the hepatic venous system.
Ultrasonography can detect extremely small tumors and, when
combined with serum a-fetoprotein assays, serves as an excellent
screening method for high-risk patients with longstanding cirrhosis.

11. Color Doppler ultrasound demonstrates an intralesional tangle of
vessels, the “basket” pattern, in up to 15% of cases, indicating
hypervascularity and tumor shunting.

12. Computed Tomography
Unenhanced CT scans demonstrate a large, hypodense mass with
central areas of lower attenuation that correspond to the tumor
necrosis frequently seen in HCC.
Multiphasic multidetector computed tomography (MDCT) including
nonenhanced, hepatic arterial, portal venous, and delayed phase
images is an efficient technique for determination of HCC and
preoperative staging of HCC.
HCC derives most of its blood supply from the hepatic artery,
the tumor demonstrates early enhancement during arterial
phase and is relatively hypodense on the delayed phase images
due to the early washout of contrast medium by arterial blood.

13. The tumor has a very variable appearance on the portal phase images.
Small tumors may appear as lesions of different attenuation while larger
ones almost always demonstrate central necrosis .
The capsule appears isodense or hypodense relative to the liver during
the hepatic arterial phase, and enhances on delayed CT images.

16. HCC has a tendency to invade the portal and hepatic veins so that
an enlarged venous segment that exhibits intraluminal low
attenuation is highly suggestive of tumor thrombus.
Differential diagnosis of tumor thrombus can be made through
demonstration of the expansion of the main portal vein diameter
(≥23 mm) and intrathrombus neovascularity on arterial phase
images.
It should be also noted that hepatic venous tumor thrombus may
extend into the inferior vena cava and even to the right atrium in
some cases.

18. A: CT arterial phase shows a small enhancing HCC, protruding from
the liver surface.
B: Three months later, the mass ruptured. CT arterial phase shows
hematoma over the surface of a crescent shaped enhancing nodule,
giving the “enucleation sign”.

19. FIBROLAMELLAR CARCINOMA
Fibrolamellar carcinoma (FLC) is a slow-growing tumor that arises in
normal liver.
It is composed of neoplastic hepatocytes separated into cords by
lamellar fibrous strands.
Grossly, FLC usually arises in a normal liver, with only 20% of patients
having underlying cirrhosis.
The appearance of FLC is somewhat similar to that of focal nodular
hyperplasia (FNH) in that both tumors have a central scar and multiple
fibrous septa. Hemorrhage and necrosis are rare.

20. FLC usually occurs in adolescents and adults younger than 40 years of
age and without underlying cirrhosis or other predisposing risk factors.
There is no sex predominance, and the mean survival is considerably
better than that for other types of HCC (45-60 months versus 6
months).
Alpha-fetoprotein levels are usually normal.

21. Ultrasound
Sonography typically demonstrates a large, well-defi ned, lobulated
mass with variable echotexture.
Fibrolamellar carcinoma usually is of mixed echogenicity (60% of
cases) and predominantly contains hyperechoic or isoechoic
components.
If present, the central scar may be visualized as a central area of
hyperechogenicity.

23. Computed Tomography
On unenhanced CT scans, FLC appears as a hypodense mass with a well-
defined contour.
Areas of decreased density within the tumor correspond to the central
scar or necrosis and hemorrhage.
Stellate calci fication within the central scar can also occur.
During the arterial and portal phases of dynamic enhanced CT, the
“nonscar” portion of fibrolamellar carcinoma enhances
heterogeneously.
This heterogeneous enhancement pattern during the arterial and portal
phases likely corresponds to the more vascular, cellular portions of the
tumor in comparison with the fibrous (lamellae and scar) and necrotic
portions.

26. Magnetic Resonance Imaging
FLC is hypointense or isointense with normal liver on T1- weighted
images and isointense or slightly hyperintense on T2-weighted images.
Because of its purely fibrous nature, the scar is hypointense on both T1-
and T2-weighted images.

29. HEPATOBLASTOMA
Serum AFP levels are frequently elevated (90% of cases ).
Pathologically it tends to be well defined, pseudoencapsulated, large,
unifocal lesion.
Less commonly multiple nodules or diffuse liver involvement
may be seen.
Calcification may be seen in up to one-third of patients
Hepatoblastoma is a malignant tumor of hepatocyte origin.
Hepatoblastoma is the most common primary liver tumor of childhood.
It most commonly occurs in the first 3 years of life.

30. Ultrasound
Hepatoblastoma appears as an echogenic mass that may have
shadowing echogenic foci corresponding to intratumor calcification.
Hyperechoic and/or cystic areas, corresponding to hemorrhage within
the tumor, and/or necrotic areas may be present as well.

31. CT
Usually seen as a well defined heterogeneous mass, which is usually
hypoattenuating compared to surrounding liver .
Frequently there are with areas of necrosis and haemorrhage.
Chunky, dense calcifications may be seen in approximately 40% of
cases.
After IV contrast agent administration, the tumor appears
hyperdense, in keepingwith its hypervascular nature.
In the early arterial phase, enhancement of a thick peripheral rim,
corresponding to the viable portion of the tumor, may be seen.
Invasion of perihepatic vessels or other structures can be
demonstrated

33. Magnetic Resonance Imaging
Hepatoblastoma is hyperintense on T2-weighted images and
hypointense on T1-weighted images.
Foci of high signal may be seen on T1-weighted images due to
hemorrhage. On T2-weighted images, internal septa corresponding to
fibrosis within the tumor appear as hypointense bands.
The mixed type, may demonstrate a more heterogeneous appearance
on T1- and T2-weighted images due to the necrosis, hemorrhage,
fibrosis, calcification, cartilage and fibrous septa contents.
After intravenous gadolinium administration, hepatoblastoma show
immediate diffuse (homogeneous or heterogeneous) enhancement
followed by a rapid washout.

35. INTRAHEPATIC
CHOLANGIOCARCINOMA (ICCA)
It is the second most common primary malignant hepatic tumor, it
arises from the biliary tree, and tends to have a poor prognosis and
high morbidity.
Incidence is usually in the elderly (7th
decade). M > F.
It accounts for 10% of all cholangiocarcinomas and arises in small
intrahepatic ducts.
It has an increased incidence in patients with Caroli’s disease,
sclerosing cholangitis, intrahepatic calculi and inflammatory bowel
disease.
A normal serum AFP may be helpful in suggesting ICCA rather than HCC.

36. Ultrasound
The appearance will vary according to the growth pattern.
Mass-forming intrahepatic: tumours will be homogeneous mass of
intermediate echogenicity with a peripheral hypoechoic halo of
compressed liver. They tend to be well delineated but irregular in
outline, and are often associated with capsular retraction , which if
present is helpful in distinguishing cholangiocarcinomas from other
hepatic tumours.
Periductal infiltrating intrahepatic: tumours typically are associated
with altered calibre bile duct (narrowed or dilated) without a well-
defined mass.
Intraductal: tumours are characterised by alterations in duct calibre,
usually ductectasia with or without a visible mass. If a polypoid mass is
seen, it is usually hyperechoic compared to surrounding liver

38. On unenhanced CT it is seen as a well-defined round to oval, hypodense
mass and on contrast enhanced CT scan it typically shows early
peripheral enhancement.
A delayed central enhancement is often seen which may take 5-15
minutes.
Capsule retraction and biliary dilatation adjacent to the mass are highly
suggestive of ICCA
CT

40. MR imaging also does not show any characteristic features and these
lesions are hypointense on T1W and hyperintense on T2W images.
On CEMR, smaller lesions (2-4 cm) enhance homogeneously but those >
4 cm show thick peripheral enhancement with centripetal progression.
This is akin to a hemangioma.
However, presence of satellite nodules, portal vein invasion and dilated
bile ducts favor a diagnosis of ICCA.
In addition,DWI shows restriction of diffusion unlike hemangioma.
MR Imaging

42. Metastases
Metastases are by far the most common cause of malignant focal liver
lesions, outnumbering primary malignant tumors by a factor of 18:1.
The liver is second only to regional lymph nodes as a site of metastatic
disease, and approximately 25% to 50% of all patients who die of cancer
have liver metastases at autopsy.
Colon (42%), stomach (23%), pancreas (21%), breast (14%), and lung
(13%) are the most common primary neoplasms.
The highest percentage of liver metastases occurs in primary carcinoma
of the gallbladder(77%), pancreas(70%), colon(53%), and breast(56%)
and the lowest in prostate cancer (13%).

43. Liver function tests are notoriously unreliable for detecting metastases;
they are normal in 25% to 50% of patients with metastases and can be
abnormal in any number of conditions. For this reason, imaging is the
key to both the diagnosis and serial follow-up of liver metastases.

44. Ultrasound
Ultrasound has a diagnostic sensitivity of over 90% in the detection of
metastases.
The sonographic appearance of metastatic liver disease has been
described as echogenic, hypoechoic, target, calcified, cystic, and diffuse.

45. Echogenic metastases tend to arise from a gastrointestinal origin or
from HCC . The more vascular the tumor, the more likely it is that the
lesion is echogenic.
Therefore, metastases from RCC, neuroendocrine tumors, carcinoid,
choriocarcinoma, and islet cell carcinoma also tend to be hyperechoic.
It is this particular group of tumors that may mimic a hemangioma on
sonography

46. Hypoechoic metastases are generally hypovascular and may be
monocellular or hypercellular without interstitial stroma.
Hypoechoic lesions represent the typical pattern seen in untreated
metastatic breast or lung cancer as well as gastric, pancreatic, and
esophageal tumors.
Lymphomatous involvement of the liver may also manifest as
hypoechoic masses

47. The bull’s-eye or target pattern is characterized by a peripheral
hypoechoic zone .The appearance is nonspecific and common,
although it is frequently identified in metastases from bronchogenic
carcinoma.

48. Calcified metastases are distinctive by virtue of their marked
echogenicity and distal acoustic shadowing . Mucinous adenocarcinoma
of the colon is most frequently associated with calcified metastases.
Calcium may appear as large, echogenic, and shadowing foci or, more
often, shows innumerable tiny punctate echogenicities without clear
shadowing.

49. Cystic metastases are uncommon and generally exhibit features that
distinguish them from the ubiquitous benign hepatic cyst, including
mural nodules, thick walls, fluid-fluid levels, and internal septations.
Primary neoplasms with a cystic component, cystadenocarcinoma of &
ovary ,pancreas & mucinous carcinoma of colon, may produce cystic
secondary lesions, although infrequently.
More often, cystic neoplasms result from extensive necrosis, seen most
oftenin metastatic sarcomas, which typically have low-level echoes and
a thickened, shaggy wall
Metastatic neuroendocrine and carcinoid tumors are typically highly
echogenic and often show secondary cystic change .
Large colorectal metastases may also rarely be necrotic, producing a
predominantly cystic liver mass.

52. Computed Tomography
On CT scans, metastases can be hyperdense, isodense, hypodense,
hypodense with peripheral enhancement, cystic, complex, calcified, or
diffusely infiltrating.
The CT appearance depends on tumor size and vascularity, the degree
of hemorrhage and necrosis.
Thus, individual metastatic lesions within the liver can have different CT
findings and metastases from different cell types can appear identical.

53. The majority of metastases are hypodense with an attenuation
between that of water and that of normal liver.
These lesions are usually hypovascular, & intravenous contrast medium
increases their conspicuity by increasing density of normal liver. These
lesions are best depicted during portal phase of enhancement (60s).
Colon, lung, prostate, gastric, and transitional-cell carcinoma are the
most common tumors that appear as hypovascular liver metastases.

54. Hyperdense metastases are uncommon. These lesions are usually
hypervascular, enhance rapidly & diffusely becoming isodense with
normal liver.
These lesions may be difficult to visualize on contrast enhanced CT
scans obtained during the portal venous phase of enhancement.

56. Rim enhancement of a hypodense metastasis represents a vascularized
viable tumor periphery contrasted with a hypovascular or necrotic
center.

57. Peripheral rim enhancement is a typical feature of malignant lesions
and only discontinuous nodular peripheral enhancement that matches
bloodpool is a typical feature of hemangioma.

58. Certain metastases may be cystic, having an attenuation less than
20 Hounsfield units.
Ultrasound may be needed to differentiate these lesions from
simple cysts.
Calcifications are also well demonstrated on CT scans.

59. MAGNETIC RESONANCE IMAGING
The T1 and T2 relaxation times of liver metastases vary considerably,
depending on the primary tumor, the degree of necrosis, hemorrhage,
and vascularity.
Nevertheless, the T1 and T2 relaxation times of most liver metastases
are longer than those of normal liver and shorter than those of simple
cysts or hemangiomas.
Six major morphologic patterns have been described for metastases on
MR images.

60. “Doughnut”
On T1-weighted images, metastases, because of their long T1 relaxation
time, present as a low signal intensity mass containing a distinct central
region of even lower signal intensity.
This pattern is usually seen with larger lesions and those that are prone
to undergo necrosis.
“Target”
On T2-weighted images, some metastases present with a central
smooth or irregularly rounded area of high signal intensity surrounded
by a rind of tissue with a somewhat weaker signal intensity.

61. “Amorphous”
These metastases have variable increased signal intensity with
inhomogeneous and featureless contents. The outer margins tend to be
round and indistinct.
“Halo”
These masses have a distinct but not necessarily smooth circumferential
rim of high signal intensity. The rim varies in thickness from 2 to 10 mm
and encircles a lesion of somewhat lower signal intensity.
This halo is probably a manifestation of greater water content than in
adjacent normal liver parenchyma, perhaps reflecting an edematous
reaction incited by tumor cell infiltration.

62. “Light Bulb”
These lesions are smooth, sharply defined, and round or elliptic. The
contents have high signal intensity and this may be due to complete
tumor necrosis and liquefaction or a hypervascular mass.

64. LYMPHOMA
Hepatic lymphoma can be either primary or secondary and can occur
in both Hodgkin’s disease (HD) and non-Hodgkin’s lymphoma (NHL).
The majority of lymphomas of the liver are secondary is found in more
than 50% of patients with HD or NHL.; primary lymphoma is rare.
Early in the disease, liver involvement is microscopic, but with time,
small nodules from a few millimeters to several cms in size develop.
HD of the liver is almost invariably associated with splenic
involvement, and the likelihood of hepatic disease is greater if there is
extensive splenic disease.

65. Ultrasound
On ultrasound studies, hepatic lymphoma appears as a hypoechoic
mass or masses in the tumoral form of the disease.
In the diffuse form, the echogenicity of the hepatic parenchyma may be
normal or the overall architecture of the liver may be altered.

66. Computed Tomography
CT is currently the preferred imaging method for evaluating
lymphoma of the liver, with a specifi city of almost 90% and a
sensitivity of almost 60%.
Secondary hepatic lymphoma most commonly manifests as
multiple well defined, large, homogeneous low-density masses .
Areas of diffuse infiltration by lymphoma causing hepatomegaly
may not be distinguishable from normal liver tissue by CT.
Frequently, additional areas of involvement in the spleen; para-
aortic, celiac, and periportal lymph nodes; and kidneys may be
noted.

68. Magnetic Resonance Imaging
Hepatic lymphoma is hypointense compared with normal liver on T1-
weighted images and hyperintense on T2-weighted images.
Diffuse hepatic lymphoma is more readily detectable by CT than by MR.

69. ANGIOSARCOMA
Angiosarcoma is the most common primary sarcoma in the liver .
It commonly affects patients 60–70 years of age but is also known to
occur in younger patients.
A strong male predominance has been reported, with a male-female
ratio of 4 : 1.
Angiosarcoma of the liver is a malignant tumor derived from endothelial
lining cells that occurs primarily in adults with exposure to a variety of
chemical agents and radiation.
Previous exposure to toxins such as Thorotrast, vinyl chloride,
arsenicals, & steroids.It has also been found in association with
hemochromatosis.

70. Ultrasound
Appear as either single or multiple hyperechoic masses. The echo
architecture is heterogeneous because of hemorrhage of various ages.

71. Computed Tomography
Computed tomography (CT) scans show the reticular pattern of
deposition of Thorotrast extremely well in both the liver and the spleen.
Circumferential displacement of Thorotrast in the periphery of a nodule
has been described as a characteristic finding of angiosarcoma.
When there is no evidence of Thorotrast deposition, angiosarcomas
present with single or multiple masses that are hypodense on
unenhanced CT scans except for hyperdense areas of fresh hemorrhage.

73. Magnetic Resonance Imaging
Low signal intensity on T1-W images and is high signal on T2—W
images with central areas of low signal.
Imaging features described on T2-w images include fluid-fluid levels
reflecting the hemorrhagic nature of the tumor and marked
heterogeneity with focal areas of high intensity along with septum-like
or rounded areas of low intensily.
On T1-weighted imaging, areas of hyperintensity are related to
hemorrhage.

75. EPITHELIAL HEMANGIOENDOTHELIOMA
Epithelial hemangioendothelioma (EHE) is a rare malignant
hepatic neoplasm of vascular origin that develops in adults.
Pathologically multiple tumors are usually present that tend to grow
and coalesce to form confluent masses.
This lesion usually develops in the periphery of the liver and commonly
shows calcifications corresponding to the fibrotic nature of this tumor

76. Ultrasound
Usually seen as hepatic lesions that are predominantly hypoechoic;
however, hepatic lesions can also have mixed echotexture or be
predominantly hyperechoic.
CT
Typically seen as multiple hypo-attenuating lesions in both hepatic
lobes that coalesce to form larger confluent hypo-attenuating
regions in a peripheral or subcapsulardistribution and a halo
or target pattern ofenhancement in large lesions. Subcapsular
lesion often present with capsular retraction.
MRI liver
T1: hypointense lesions relative to normal liver parenchyma on
unenhanced T1-weighted images
T2: heterogeneously increased signal intensity.

78. Thank you..