Paediatric liver tumors

1. PAEDIATRIC LIVER TUMORS
DR ARUN KUNCHERIA JOSEPH

2. Congenital masses
Hepatic cyst
Choledochal cyst
Primary neoplasm
Infantile hepatic hemangioma
Hepatic adenoma
Focal nodular hyperplasia
Mesenchymal hamartoma
Regenerative nodule
Hepatoblastoma
Hepatocellular carcinoma
Fibrolamellar carcinoma
Undifferentiated (embryonal)
sarcoma
Angiosarcoma
Lymphoma
Metastatic disease
Infection
Bacterial infection
Fungal infection
Parasitic infection
Mimics
Focal fatty proliferation
Hepatic infarction
Extrahepatic masses

3. Congenital Masses

4. 1.HEPATIC CYST
● a benign congenital lesion that results from abnormal development of intrahepatic biliary
ducts and does not communicate with the biliary tree
● Incidentally detected
● large hepatic cysts may present with abdominal pain and distention.
● Common complications
-intracystic infection
-bleeding.
● Multiple hepatic cysts (> 10) - polycystic liver disease to be considered.

5. ● Imaging
● USG - Simple hepatic cysts are typically unilocular, thin-walled, anechoic
masses without septation, mural nodules, or internal vascularity on ultrasound.
● CT and MRI - round nonenhancing masses with an imperceptible wall and follow
the attenuation and signal intensity of water.
● Treatment
- surgical resection if their size is large or recurrent superimposed infection.
- Small asymptomatic cysts do not require treatment.

7. 2.CHOLEDOCHAL CYST
● rare congenital malformations of the intrahepatic or extrahepatic biliary ductal
systems
● Girls >boys
● More prevalent in Eastern countries
● Triad of abdominal pain, palpable right upper quadrant mass, and jaundice

9. ● Imaging
● Ultrasound
dilated cystic lesion which communicates with the bile duct and is separate from the
gallbladder.
● CT / MRI
Findings are similar to ultrasound, with a greater ability to demonstrate intrahepatic disease
and complications.
● Complications
■ stone formation: most common
■ malignancy - cholangiocarcinoma
■ the cyst may rupture leading to bile peritonitis -most frequently seen in neonates
■ pancreatitis

11. Neoplasms

12. 1. INFANTILE HEPATIC HEMANGIOMA
formerly referred to as infantile hemangioendothelioma
benign vascular tumor of the liver that is lined by endothelium
most common benign hepatic tumor in infants
Subtypes - focal, multifocal and diffuse

13. -hepatic form of cutaneous rapidly
involuting congenital hemangioma
(RICH)
-no association with cutaneous
hemangioma
-no sex prediliction
- vascular mass fully formed at birth
- does not increase in size
postnatally
- involutes completely by 12–14
months
-negative for glucose transporter
protein-1 (GLUT1).
hepatic form of simple
cutaneous infantile
hemangioma
-associated with
cutaneous hemangiomas
-female predilection
-present before the age of
6 months
-positive for GLUT1
-complete replacement of
hepatic parenchyma by
infantile hemangiomas
-large palpable abdominal mass
and develop high-output heart
failure because of
arteriovenous shunting
FOCAL
MULTIFOCAL
DIFFUSE

14. Imaging
● USG- heterogeneous but predominantly hypoechoic solid masses
● CT - low-attenuation masses that may contain calcification. After IV contrast
administration, there is early peripheral and nodular enhancement with
variable delayed central enhancement.
● MRI- hypointense on T1-weighted images and hyperintense on T2-weighted
images. The contrast enhancement pattern is similar to that seen on CT.

17. 2.HEPATIC ADENOMA
● benign tumor derived from hepatocytes
● Females
● Risk factors
-oral contraceptive/ anabolic steroid use in adolescent or older children
-underlying diabetes mellitus
-glycogen storage disease.
● Complications- hemorrhage, necrosis, and fatty change

18. ● Imaging
● USG -heterogeneous solid masses that show internal vascularity
● CT - hypodense on unenhanced CT (lipid content). Variable pattern of
enhancement with washout of contrast material on delayed images.
● MRI -depends on the amount of fat, hemorrhage, and necrosis within the lesion -
heterogeneous on both T1- and T2-weighted images. Heterogeneous early post
contrast enhancement with subsequent washout but delayed pseudocapsule
enhancement.
● MRI with chemical shift or fat-suppression techniques is particularly useful in
detecting adenomas with high lipid content.

20. 3.FOCAL NODULAR HYPERPLASIA
● benign hepatic mass consisting of hyperplastic parenchymal nodules with abundant
abnormal vessels.
● 4% of all primary hepatic tumors in the pediatric population
● usually found incidentally.
● Also can be a late complication in patients with a history of previously treated malignancy
- possibly linked to treatment-related vascular damage

21. ● Imaging
● USG - well-circumscribed solid hepatic mass with a central hypoechoic scar. There may
be a spoked wheel pattern of vascularity
● CT - isodense to normal hepatic parenchyma on plain images ; avid post contrast
enhancement of FNH, with delayed enhancement of the central scar.
● MRI - isointense to normal liver and the central scar is hypointense on T1-weighted
images and mildly hyperintense on T2-weighted images ; early arterial enhancement of
the mass with delayed enhancement of the central scar.
● Technetium-99 cu m sulfur colloid scanning can also be used to identify FNH, which
shows normal or increased uptake because of the presence of Kupffer cells.

23. 4.MESENCHYMAL HAMARTOMA
● cystic hepatic tumor
● second most common benign hepatic liver mass in the pediatric
population.
● detected in patients under the age of 2 years
● boys > girls.
● Clinical Features - enlarging abdominal mass / asymptomatic.

24. Imaging
● USG - multiseptated cystic mass with little or no internal vascularity.
● CT and MRI - multiseptated mass of water attenuation and signal intensity, respectively.
The thin internal septations may show contrast enhancement.
● Mesenchymal hamartoma most commonly involves the right hepatic lobe and is not
typically associated with calcification or hemorrhage

26. 5.REGENERATIVE HEPATIC NODULE
● referred to as “nodular regenerative hyperplasia,”
● rare disorder consisting of diffuse micronodular transformation of hepatic
parenchyma without intervening fibrous septa.
● a regenerative hepatic nodule is thought to represent a hyperplastic response
of hepatocytes to small-vessel disease and ischemia

27. ● If regenerative hepatic nodules are small (≤ 0.5 cm), CT and MRI may show a
normal appearance of the liver.
● Larger regenerative hepatic nodules (0.5–4.0 cm) may appear on CT as focal
nodules that are isodense to normal hepatic parenchyma and show diffuse
contrast enhancement.
● MRI- regenerative hepatic nodules are isointense on T1- weighted images
and iso- to hypointense on T2-weighted images.
● As with CT, they usually show diffuse contrast enhancement.

29. 6. HEPATOBLASTOMA
● malignant hepatic tumor of epithelial and mesenchymal cell origin.
● most common hepatic malignancy in the pediatric population
● boys > girls (2:1).
● have an elevated serum α-fetoprotein level.
● Metastatic disease is common - lung - most common site.
● Clinical features- large, painless abdominal mass.

30. Imaging
● USG - well-circumscribed heterogeneous mass that is generally located in the right
lobe of the liver. Calcifications are present in approximately 50% of cases. Areas of
hemorrhage / necrosis and tumor vascularity may be identified.
● CT - hepatoblastoma is usually hypodense on unenhanced images and typically is
heterogeneous after contrast administration, although to a lesser degree than
normal hepatic parenchyma
● MRI - hypo on T1-weighted and hyper on T2. MRI signal characteristics of
hepatoblastoma may vary if there is associated hemorrhage and necrosis. The
tumor typically shows heterogeneous contrast enhancement

32. 7.HEPATOCELLULAR CARCINOMA (HCC)
● most common primary hepatic malignancy in adults but is rarely seen in the
pediatric population.
● Affected children are usually older than 13 years.
● When occurring in the pediatric population, HCC is likely to be more extensive
and the prognosis is poor.
● associated with an elevated serum α-fetoprotein level
● Most patients have underlying cirrhosis of the liver.

33. ● Contrast-enhanced CT and MRI are the current imaging modalities of choice
● The characteristic imaging appearance of HCC is early arterial enhancement
followed by venous washout. Capsule may be seen on delayed images.

35. 8. FIBROLAMELLAR CARCINOMA
● rare malignant tumor of the liver that differs clinically and radiologically from
conventional HCC.
● Accounts for less than 10% of all HCCs. Unlike conventional HCC, fibrolamellar
carcinoma typically arises within normal liver parenchyma and there are no
specific risk factors or elevated α-fetoprotein levels.
● Patients with fibrolamellar carcinoma present at a younger age (second or third
decade of life) than those with conventional HCC.
● The prognosis of fibrolamellar carcinoma is more favorable, with a 5-year
survival rate of approximately 67%.

36. ● Imaging
● CT - Large solitary well-defined mass that is hypodense and heterogeneous.The
central scar, when present, is usually hypodense, and there may be associated
calcification and necrosis. Most lesions show heterogeneous contrast enhancement.
● MRI - fibrolamellar carcinoma is slightly hypointense on T1- weighted images and
hyperintense on T2-weighted images and usually shows intense heterogeneous
enhancement. The central scar appears hypointense on both T1-weighted images
and T2-weighted images.
● There is usually no enhancement of the central scar on arterial or portal venous
phases, but the central scar may partially enhance on delayed phase images.

38. 9. UNDIFFERENTIATED (EMBRYONAL) SARCOMA
● rare malignant hepatic neoplasm that occurs primarily in children between 6–
10 years old.
● Clinical features - abdominal pain, fever, and weight loss.
● not associated with elevated serum α-fetoprotein levels
● prognosis is poor
● median survival of less than 1 year.

39. ● Imaging
● USG -usually presents as a heterogeneous solid hepatic mass with borders
that are often ill defined.
● CT - hypodense on plain images
● MRI -heterogeneously hyperintense on T2
● After contrast administration, there is usually delayed enhancement of
undifferentiated (embryonal) sarcoma on both CT and MRI.

41. 10. ANGIOSARCOMA
● malignant spindle cell tumor of the liver derived from endothelial cells.
Although more commonly seen in older adult patients, it can also rarely occur
in pediatric patients.
● Early metastases are common and the prognosis is poor, with a median
survival of 6 months.
● Risk factors for developing angiosarcoma include exposure to environmental
carcinogens, cyclophosphamide, anabolic steroids, and prior radiation.
● Angiosarcoma is prone to rupture and hemorrhage.

42. Imaging
● USG- heterogeneous mass with marked internal vascularity.
● CT - solitary / multiple hypodense masses. Areas of increased density on CT typically
represent underlying hemorrhage. There is usually heterogeneous early contrast
enhancement and progressively homogeneous enhancement during the delayed
phase.
● MRI - hypointense on T1 and heterogeneous but predominantly hyperintense on T2.
Areas of T1 hyperintensity or T2 hypointensity of the tumor are related to underlying
hemorrhage or hemosiderin. There is heterogeneous contrast enhancement during
the arterial phase, with progressive enhancement on delayed images.

44. 11. LYMPHOMA
● Both Hodgkin disease and non-Hodgkin lymphoma (NHL) involve the liver in
more than one half of patients.
● Primary hepatic lymphoma is rare.
● Secondary lymphomatous involvement of the liver is more common in both
pediatric and adult patients.
● Secondary hepatic lymphoma is seen in over half of patients with Hodgkin
disease or NHL.
● Risk factors for developing primary hepatic lymphoma include
immunosuppressed status due to prior transplantation or an infectious
process, such as AIDS.

45. ● Imaging
● CT- primary hepatic lymphoma may appear isodense to hypodense compared
with normal hepatic parenchyma. Secondary hepatic lymphoma typically
appears as multiple hypodense lobulated masses. However, the infiltrative
type of hepatic lymphoma may present as a diffusely hypodense liver. Hepatic
lymphoma does not show substantial contrast enhancement.
● MRI- lymphoma is hypointense on T1-weighted images and hyperintense on
T2-weighted images and usually shows only minimal contrast enhancement.

47. 12. METASTATIC DISEASE
● Liver is a common site for malignant spread of neoplasms.
● Hepatic metastatic disease is much more common than primary hepatic
malignancy in the pediatric population.
● Hypovascular liver metastases usually originate from lung, gastrointestinal
tract, and pancreatic tumors.
● Hypervascular metastases arise from endocrine, renal, and sarcomatous
tumors.
● In the pediatric population, the most common primary tumors that metastasize
to the liver are neuroblastoma and Wilms tumor.

48. Imaging
Abdominal radiographs - an enlarged liver may suggest possible hepatic
metastatic disease in pediatric oncology patients.
CT- metastases usually produce multiple focal hypodense or hyperdense masses
of varying size that are distributed randomly throughout the liver parenchyma
MRI - hypointense on T1. On T2-weighted images, there is variable signal intensity
(usually ranging from intermediate to high signal intensity).
Hypovascular metastases may show peripheral contrast enhancement with a
nonenhancing or necrotic center on both CT and MRI, whereas hypervascular
metastases show early arterial phase enhancement.

50. Infections

51. 1. BACTERIAL INFECTION
● development of a hepatic pyogenic abscess, which results from destruction of
hepatic parenchyma and formation of localized collections of pus.
● rare in pediatric patients.
● Most common bacterial organisms causing hepatic pyogenic abscess in the
pediatric population is Staphylococcus aureus. ( Escherichia coli is the most
frequent offending bacterial organism in adults).

52. can occur via several different pathways:
● hematogenous spread of infection via the hepatic artery
● portal venous spread from intestinal infectious processes
● biliary spread related to cholangitis
● direct extension from other intraabdominal infectious processes
● secondary infection after blunt or penetrating trauma

53. ● Imaging
● USG - variable echogenicity, with approximately one half appearing anechoic. Usually
spherical or ovoid and may be surrounded by an irregular hypoechoic or echogenic wall.
● CT - well defined single hypodense mass / hypodense mass with multiple septations,
representing a cluster of multiple small abscesses. Internal gas is present in about 20%
cases. Contrast enhancement usually occurs along the periphery of an abscess and
may involve internal septa.
● MRI - T1 - hypointense, T2 - hyperintense . There may be increased T2-weighted signal
in the adjacent hepatic parenchyma, representing edema or inflammatory
changes.Peripheral rim and septal contrast enhancement.

54. 2. FUNGAL INFECTION
Result of dissemination from systemic disease.
Risk factors - immunocompromised due to neutropenia after treatment of
hematologic malignancies, transplantation, AIDS, and chronic granulomatous
diseases of childhood.
The most common fungi causing hepatic infection are Candida species,
specifically C. albicans.
The most frequent route of infection is via intestinal seeding of the portal venous
circulation.

55. ● Imaging - numerous microabscesses (< 1 cm) that are distributed diffusely throughout the liver.
● The appearance of fungal infection on ultrasound depends on the phase of infection and
treatment.
● During the early phase of infection, there are focal hypoechoic lesions with alternating
echogenic and hypoechoic peripheral zones.
● As the infection progresses, the lesions are usually hypoechoic with echogenic centers,
producing a targetlike configuration. After the institution of antifungal therapy, the lesions
become smaller and echogenic and may resolve completely.
● Unenhanced CT of pediatric patients with hepatic fungal infection shows multiple small
hypodense lesions that often show scattered calcifications during the healing phase. The central
portion of lesions is typically nonenhancing with variable degrees of peripheral enhancement.
The presence of central or eccentric enhancement is thought to represent hyphae.

56. ● MRI - current imaging modality of choice when evaluating pediatric patients
suspected of hepatic involvement with disseminated fungal infection because of its
high sensitivity for detecting small hepatic lesions and the lack of exposure to
ionizing radiation.
● Hepatic fungal lesions are hypointense on T1-weighted images, hyperintense on
T2-weighted images, and do not show substantial contrast enhancement

58. 3. PARASITIC INFECTION -
a. AMOEBIC ABSCESS
● The most common causative organism is Entamoeba histolytica.
● rare in the pediatric population
● more common in developing countries
● Initial infection with the cystic form of E. histolytica is by contaminated water.
After cysts enter the gastrointestinal tract and their cystic walls become
digested, trophozoites are released into the intestines.
● Hepatic involvement occurs by portal venous and lymphatic spread; rarely, it
may develop by direct extension from the colon.

59. Imaging
● USG - well-defined hypoechoic mass with through-transmission.
● CT - unilocular or multilocular peripheral hypodense mass with a thick
enhancing capsule.
● MRI - the lesions are hypointense on T1- weighted images and hyperintense
on T2- weighted images, often with evidence of edema in the surrounding
hepatic parenchyma. As with CT, enhancement of a thick peripheral capsule
is often seen on MRI

61. B. HEPATIC ECHINOCOCCAL OR HYDATID DISEASE
● Causative organism - E. granulosus - results in hydatid disease. E. multilocularis - produces a
diffuse infiltrative process.
● Affected pediatric patients are usually asymptomatic but may become symptomatic with
progressive infection and cyst rupture.
● Aspiration of a hydatid cyst is associated with a risk of anaphylactic reaction if there is spillage
of cyst contents into the peritoneal cavity.
● The hydatid form of hepatic echinococcosis typically presents as a dominant cystic lesion that
contains multiple peripheral daughter cysts.
● USG- hydatid cysts are well defined and predominantly anechoic, with some echogenic
contents present between daughter cysts. The “water lily” sign refers to a cyst containing a
floating membrane with a detached endocyst that develops after cyst rupture.

62. ● CT - the mother cyst is hypodense, with the daughter cysts even more hypodense
relative to the dominant cyst. Peripheral rim calcifications are often seen, particularly
during the healing phase of the disease. The fibrous cyst wall and internal septa typically
show contrast enhancement.
● MRI - T1- the mother cyst has intermediate signal intensity and daughter cysts are
hypointense. The rim and any internal floating membranes are hypointense. T2 - both the
mother and daughter cysts have variable hyperintensity, although the rim and floating
membranes are hypointense. Both the cyst wall and septa enhance after contrast
administration.
● On MRI, infiltrative echinococcal lesions are heterogeneous and show mild contrast
enhancement. Calcifications are difficult to detect on MRI. Transdiaphragmatic spread to
the thoracic cavity is more common with the infiltrative form of hepatic echinococcosis.

64. Conditions That Can Mimic Focal
Hepatic Masses

65. 1. HEPATIC FATTY PROLIFERATION
● May result from toxic, ischemic, or infectious liver insults.
● more commonly occurs in the adult population and may be associated with
underlying diabetes and obesity.
● Affected patients are typically asymptomatic.
● may be focal or diffuse.
● In the diffuse type, there may be areas of focal sparing that can often be
confused with true hepatic lesions. Focal sparing usually occurs in hepatic
segment IV and often borders the gallbladder fossa

66. ● USG- areas of steatosis are hyperechoic, with poor visualization of portal and
hepatic veins in the involved segments. Focal sparing is seen as a relatively
hypoechoic lesion in an otherwise echogenic liver.
● CT - areas of fatty liver involvement are hypodense relative to the spleen. The
most common location for focal fatty infiltration is the watershed zone adjacent
to the falciform ligament. Diffuse steatosis with focal sparing presents as a
relatively hyperdense focus within an otherwise hypodense liver. After contrast
administration, normal vessels can be seen coursing through areas of steatosis.
● MRI - with chemical-shift imaging is helpful in the evaluation of hepatic steatosis.
Involved areas have increased signal intensity relative to the spleen on T1-
weighted in-phase gradient echo sequences and show loss of signal on
opposed-phase sequences. No enhancement with gadolinium.

68. 2. HEPATIC INFARCTION
represents areas of necrosis due to ischemia caused by disrupted hepatic
perfusion.
Relatively rare because of the presence of a dual blood supply via the hepatic
arterial and portal venous systems. Hepatic infarction may be secondary to
thrombus or embolus.
Hepatic infarction due to arterial thrombus is a relatively common (up to 12%)
complication of liver transplantation in the pediatric population.
Hepatic infarction include trauma, infection, vasculitis, hypercoagulable states, and
iatrogenic postsurgical complications.

69. Imaging :
● USG - appears hypoechoic on ultrasound. Color Doppler imaging may show
absence of normal hepatic arterial blood flow; less commonly, findings of portal
vein thrombosis may be identified.
● CT - appears as a hypodense area with sharply defined margins. Because of
perfusion defects, lesions are often more conspicuous after contrast administration
and remain hypodense on all phases of contrast-enhanced imaging.
● MRI - signal characteristics reflect edema within the lesion, which appears
hypointense relative to normal hepatic parenchyma on T1and hyperintense on T2.
No post contrast enhancement because of perfusion defects and necrosis.

71. EXTRAHEPATIC MASSES
Various other lesions in the right upper abdominal quadrant may be confused with
focal hepatic masses.
These include masses arising from the right adrenal gland (neuroblastoma) and
right kidney (Wilms tumor or other primary renal masses) . Lymphadenopathy in
the porta hepatic related to metastatic disease or lymphoma also may mimic an
exophytic hepatic lesion

72. LESION SPECIAL CHARACTERISTICS
Infantile hemangioma Peripheral nodular enhancement on arterial phase with centripetal filling
FNH Central scar - T2 hyperintense - delayed contrast enhancement
Adenoma Fat content (not always seen), may contain hemorrhage
Regenerative nodules Hypointense on T2
Focal fatty infiltration GB fossa, near falciform ligament, no distortion of vessels
Hepatoblastoma Large , heterogenous, multilobulated, hypointensity on all phases with scattered T1
hyperintense foci
HCC Early enhancement and washout. Capsule in delayed phase. Diffusion restriction.
Metastases Multiple nodules varying sizes.
Mesenchymal Hamartoma Predominantly cystic appearance with thick septa and some solid components. Seen in
infancy
Undifferentiated embryonal
sarcoma
Solid cystic appearance - seen in children older than 6 years

73. THANK
YOU

74. QUIZ

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