This document provides an overview of cystic hepatic lesions and an approach to their diagnosis. It discusses the differential diagnoses for cystic lesions, which range from benign to malignant conditions. Key imaging features like the presence of solid components or cyst morphology and number are important to consider along with clinical data. The document then categorizes and describes various developmental, inflammatory, neoplastic, and trauma-related cystic lesions of the liver in detail, noting their typical appearance on ultrasound, CT, and MRI. It proposes using these imaging characteristics and clinical information to establish a definitive diagnosis or reasonable differential diagnosis for cystic hepatic lesions.

1. An Approach to Cystic
Hepatic Lesions
Dr. Jiten Kumar
Moderator: Dr. G.Prem Kumar

2. OBJECTIVES
O review the appearance of different cystic
hepatic lesions on imaging
O propose a practical algorithm for
approaching the diagnosis
O establish a definitive diagnosis or provide
a reasonable differential diagnosis

3. Hepatic cystic lesions
O differential diagnoses range from benign
to malignant and potentially lethal
conditions
O key radiologic features in combination with
reviewing the clinical data important
O key imaging features
O solid component
O number and morphology

4. Classification
Developmental Inflammatory Neoplastic Trauma-
related
Simple cyst Pyogenic
abscess
Biliary
cystadenoma
spectrum
Biloma
Biliary
hamartoma
Amebic abscess Cystic HCC Seroma and
hematoma
Caroli disease Hydatid cyst Cystic metastasis
Polycystic liver
disease
Fungal
microabscess
Undifferentiated
embryonal
carcinoma
Ciliated foregut
duplication cyst
Intrahepatic
pseudocyst

5. Developmental
Lesions

6. Hepatic Cysts
O most commonly encountered hepatic lesion
O deranged development of the biliary tree (i.e., a
hamartoma of biliary origin or so-called “von
Meyenburg complex”
O no communication with the biliary tree
O ultrasound features
O well-marginated , anechoic round to ovoid
structure with an imperceptible wall
O enhancement of the posterior wall and increased
through-transmission
O CT and MRI,
O simple cysts have attenuation (0–15 HU) and
signal intensity (T1 hypointensity, T2
hyperintensity) similar to water
O Simple cysts do not show enhancement; can rarely
become complex

7. Hepatic Cysts

8. Biliary Hamartoma (von Meyenburg
Complex)
O dilated small bile ducts surrounded by fibrous
stroma
O ductal plate malformation
O lack of communication with biliary system
O multiple, small (< 15 mm), round or irregular
scattered cysts with predilection for the
subcapsular region
O ultrasound findings
O Variable- might appear anechoic, hypoechoic,
or hyperechoic,sometimes comet-tai artefacts
O CT and MRI -simple cystic appearance

9. Biliary Hamartoma

10. Caroli Disease
O saccular dilatation of large intrahepatic bile ducts,
O associated with other diseases along the spectrum
of ductal plate malformations (e.g., biliary
hamartomas, polycystic liver disease, or hepatic
fibrosis), polycystic kidney disease, or renal tubular
ectasia
O Caroli disease and hepatic fibrosis is designated
as Caroli syndrome
O Caroli disease is classified as type V in the revised
Todani classification of biliary cysts
O become symptomatic by the age of 30 years
O Complications include recurrent cholangitis and
abscess, stone formation, cholangiocarcinoma,
and the development of secondary biliary cirrhosis

11. Caroli Disease
O multiple intrahepatic cysts of varying sizes
that communicate with the biliary system
O diffuse or localized to one segment or one
lobe, usually the left lobe
O On CT and MRI
O lesions are cystic and usually have a
central enhancing component, the “central
dot” sign, which is the portal radicle
O communication with the biliary system can
be further confirmed on cholangiography

12. Caroli Disease

13. Polycystic Liver Disease
O can be associated with ADPKD, which is found in
50% of these patients
O maldevelopment of the ductal plate that affects the
small intrahepatic bile ducts
O Histologically, two types of cysts
O intrahepatic cysts -usually peripherally located and
vary in size from a few millimeters to 80 mm
O peribiliary cysts are typically small (< 10 mm) and
have a periportal distribution
O complications include cyst hemorrhage, rupture, or
superinfection.
O CT findings suggestive of cyst infection –
O development of a fluid level, wall thickening,
calcification, or internal gas
O MRI is the best modality for identifying cysts
complicated by hemorrhage or infection

14. Polycystic Liver Disease

15. Ciliated Hepatic Foregut Duplication
Cyst
O rare congenital cystic lesion thought to arise from the
embryonic foregut- many similarities with a bronchogenic
cyst
O solitary lesion that typically measures less than 3
O most commonly located in the subcapsular aspect of segment
IV
O few cases of malignant transformation to squamous cell
carcinoma have been reported
O symptomatic, enlarging, larger than 4 cm, or containing
atypical features (e.g., solid components, thick septations)
should be resected
O ultrasound: anechoic or hypoechoic
O The cyst content ranges from clear serous fluid to mucous
fluid of different viscosities- - CT attenuation and T1 signal
intensity vary
O high signal intensity on T2-weighted imaging, no
enhancement on MRI

16. Ciliated Hepatic Foregut
Duplication Cyst

17. Inflammatory Lesions

18. Pyogenic Liver Abscess
O risk factors
O diabetes,
O gastrointestinal tract cancers,
O diverticulitis, cholangitis, cholecystitis
O recent hepatobiliary surgery or trauma
O more likely to form in the right lobe
O ultrasound- an anechoic mass with
O well-defined or indistinct borders
O increased through transmission
O may contain echogenic debris or gas
O with Klebsiella, more likely to be solid
O CT-
O iso- to hypoattenuating compared with background liver on the
unenhanced phase
O peripheral rim of enhancement on administration of IV contrast
O MRI
O the central portion of the lesion will show low signal intensity on T1-
weighted imaging and high signal intensity on T2-weighted imaging
O a peripheral halo of hyperintensity indicating edema may be seen on T2-
weighted imaging.

19. Pyogenic Liver Abscess

20. Amebic Liver Abscess
O amebic and pyogenic liver abscesses are virtually
indistinguishable on imaging
O diagnosis on the basis of clinical and serologic findings
O Extrahepatic disease, such as a right pleural effusion, a
pericardial effusion, or intraperitoneal rupture may suggest an
amebic abscess
O typically solitary most often in the posterior segment
O ultrasound-
O hypoechoic round or oval lesions located close to the liver
capsule
O show low-level internal echoes and posterior acoustic
enhancement
O CT-
O slightly higher attenuation than water may have smooth or
nodular borders
O thick (3–15 mm) wall that typically enhances
O MRI
O the central portion cystic,
O “rind” exhibits variable intensities on T1- and T2-weighted
imaging

21. Amebic Liver Abscess

22. Hydatid Cyst
O symptoms include pain; biliary obstruction;
superinfection; and, rarely, cyst rupture, which can
lead to anaphylactic reaction
O On imaging, the lesions present as unilocular or
multilocular cysts
O Four different radiographic appearances
O simple cyst with no internal architecture
O cyst with daughter cysts and a matrix
O calcified cyst
O complicated cyst
O The classic type is a cyst containing multiple
peripheral daughter cysts
O content of the daughter cysts is different from that of
the mother cyst- daughter cysts are usually
hypodense on CT and have a slightly different signal
intensity than the mother cyst on MR

23. Hydatid Cyst

24. Fungal Microabscesses
O typically seen in the immunocompromised population
O small lesions(< 2 cm) and disseminated throughout the
liver and the spleen, sometimes renal
O Ultrasound appearance
O “bull’s eye”: a round hyperechoic lesion with an outer
hypoechoic ring
O “wheel within a wheel”- adding a central hypoechoic dot to
the bull’s eye
O CT
O triphasic liver imaging is most sensitive
O most lesions being detectable on the arterial phase as
uniformly hypoattenuating
O MRI
O most conspicuous on the T2
O Mimics of hepatosplenic fungal infection include
granulomatous diseases (e.g., sarcoidosis) and rarely
aseptic abscesses

25. Fungal Microabscesses

26. Intrahepatic pseudocyst
O extremely rare condition- usually as a complication
of acute alcoholic pancreatitis
O affect young and middle-age men
O high propensity for the right lobe
O ancillary findings of pancreatitis is key
O spread of pancreatic enzymes and lesser sac fluid
along the hepatogastric and hepatoduodenal
ligaments or the portal triad into the liver
parenchyma intrahepatic tissue damage
and necrosis
O can spontaneously resolve or can progress to
become a pseudocyst with a fibrous capsule
O On imaging, the lesions manifest as a simple fluid
collection with an enhancing thin peripheral
capsule

27. Neoplastic Lesions

28. Biliary Cystadenoma (BCA) and
Cystadenocarcinoma (BCAC)
O more common in women: mean age at presentation is 45
years for BCA and almost 55 years for BCAC-
O the female predominance is much more pronounced in BCA
(female/male ratio- 9:1)
O arise from ectopic rests of embryonic bile ducts or aberrant
ducts- majority intrahepatic
O BCAC is usually a result of malignant transformation of BCA
(risk as high as 20%) but can also arise de novo
O imaging findings overlap
O multilocular with enhancing walls,
O fine septations, and variable calcification
O can be as large as 30 cm
O biliary ductal dilatation in the left lobe common
O Enhancing mural nodules are more common in BCAC than
BCA
O can mimic that of pyogenic abscess, amebic abscess, or
cystic metastasis

29. Biliary Cystadenoma (BCA) and
Cystadenocarcinoma (BCAC)

30. Biliary Cystadenoma (BCA) and
Cystadenocarcinoma (BCAC)

31. Cystic Hepatocellular Carcinoma
O Classically HCC is a hypervascular mass with
rapid washout on the portal venous phase and
an enhancing peripheral capsule
O Very rarely, may manifest as a predominantly
cystic mass with enhancing septa- an irregular
multilocular hypoattenuating lesion with a
peripheral rim of enhancement
O hypoattenuating central portion is necrosis and
the peripheral enhancing septa contain
malignant cells
O liquefactive necrosis after locoregional
treatment is a more common cause for the
cystic morphology

32. Cystic Hepatocellular Carcinoma

33. Cystic Liver Metastases
O 10% of focal liver lesions in patients with a known
primary are found to be metastatic disease-
O neuroendocrine tumors,
O gastrointestinal stromal tumor (GIST),
O lung adenocarcinoma, colorectal carcinoma,
O transitional cell carcinoma, adenoid cystic
carcinoma,
O ovarian carcinoma, choriocarcinoma, sarcoma,
O Cause of cystic appearance
O high mucinous content
O rapid growth of the tumor with hemorrhage,
necrosis, or cystic degeneration
O cystic degeneration after chemotherapy
O hypoattenuating to background liver on CT ,usually
irregular peripheral rim of enhancement

34. Cystic Liver Metastases

35. Undifferentiated Embryonal Sarcoma
(UES)
O highly malignant hepatic neoplasm: the pediatric age
group (typical age at presentation, 6–10 years)
O mesenchymal origin with sarcomatous features
O large (> 10 cm) solitary lesion commonly in the right lobe
O ultrasound- solid iso to hyperechoic with small anechoic
areas corresponding to areas of necrosis or cystic
degeneration
O CT
O unenhanced CT-cystic with near-water attenuation: high
water content of its myxoid stroma
O Contrast-enhanced CT can show different degrees of
enhancement
O MR
O cystic on unenhanced T1- and T2-weighted sequences
O heterogeneous enhancement post contrast -better seen in
the late portal venous phase

36. Undifferentiated Embryonal Sarcoma

37. Undifferentiated Embryonal Sarcoma

38. Trauma-related

39. Oma-s
O Post trauma or iatrogenic injury ,collection of
O bile-biloma,
O lymph- seroma
O blood- hematoma
O Inflammatory response leads to pseudocapsule
formation
O On imaging,
O seromas and bilomas appear as a simple fluid collection
that may or may not show a thin rim of enhancement
O Hematomas, on the other hand, have different density
and intensity based on the age of the blood products.
O GRE T2-weighted sequence—the most sensitive
method for detecting blood products

40. Oma-s

41. Approach

42. Mimics
O Pseudoaneurysm
O cystic on ultrasound and on unenhanced
CT
O vascular nature established on color and
spectral Doppler imaging.
O Contrast-enhanced CT and MRI show
enhancement similar to the blood pool.
O Focal Steatosis
O nodular steatosis rarely can mimic a cystic
lesion on unenhanced CT
O MRI with the use of chemical-shift gradient-
echo imaging

43. Mimics
O Peribiliary Cyst
O obstruction of the neck of the periductal glands
O high association with cirrhosis, portal
hypertension, and AD polycystic disease
O lesions usually increase in size and number as
cirrhosis and portal hypertension progress
O located along the portal tracts in the hilum and
adjacent to the large intrahepatic ducts
O discrete, clustered, or confluent
O The confluent type can mimic biliary ductal
dilatation
O Ultrasound can depict the thin septa between the
cysts to differentiate them fromprimary sclerosing
cholangitis

44. Peribiliary Cyst

45. Thank You…