An Approach to Cystic Hepatic Lesions Dr. Jiten Kumar Moderator: Dr. G.Prem Kumar
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An Approach to Cystic Hepatic Lesions
Dr. Jiten Kumar
Moderator: Dr. G.Prem Kumar
OBJECTIVESO 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
Hepatic cystic lesionsO 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 featuresO solid componentO number and morphology
ClassificationDevelopmental
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
Developmental Lesions
Hepatic CystsO most commonly encountered hepatic lesionO 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 treeO 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
Hepatic Cysts
Biliary Hamartoma (von Meyenburg Complex)
O dilated small bile ducts surrounded by fibrous stroma
O ductal plate malformationO lack of communication with biliary systemO multiple, small (< 15 mm), round or
irregular scattered cysts with predilection for the subcapsular region
O ultrasound findingsO Variable- might appear anechoic,
hypoechoic, or hyperechoic,sometimes comet-tai artefacts
O CT and MRI -simple cystic appearance
Biliary Hamartoma
Caroli DiseaseO 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 yearsO Complications include recurrent cholangitis and
abscess, stone formation, cholangiocarcinoma, and the development of secondary biliary cirrhosis
Caroli DiseaseO multiple intrahepatic cysts of varying sizes
that communicate with the biliary systemO diffuse or localized to one segment or one
lobe, usually the left lobeO 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
Caroli Disease
Polycystic Liver DiseaseO can be associated with ADPKD, which is found in 50% of
these patientsO maldevelopment of the ductal plate that affects the
small intrahepatic bile ductsO 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 gasO MRI is the best modality for identifying cysts
complicated by hemorrhage or infection
Polycystic Liver Disease
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 reportedO symptomatic, enlarging, larger than 4 cm, or containing
atypical features (e.g., solid components, thick septations) should be resected
O ultrasound: anechoic or hypoechoicO 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
Ciliated Hepatic Foregut Duplication Cyst
Inflammatory Lesions
Pyogenic Liver AbscessO risk factors
O diabetes,O gastrointestinal tract cancers,O diverticulitis, cholangitis, cholecystitisO recent hepatobiliary surgery or trauma
O more likely to form in the right lobeO ultrasound- an anechoic mass with
O well-defined or indistinct borders O increased through transmission O may contain echogenic debris or gasO with Klebsiella, more likely to be solid
O CT-O iso- to hypoattenuating compared with background liver on the
unenhanced phaseO peripheral rim of enhancement on administration of IV contrast
O MRIO the central portion of the lesion will show low signal intensity on T1-
weighted imaging and high signal intensity on T2-weighted imagingO a peripheral halo of hyperintensity indicating edema may be seen on T2-
weighted imaging.
Pyogenic Liver Abscess
Amebic Liver AbscessO amebic and pyogenic liver abscesses are virtually
indistinguishable on imagingO 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 segmentO ultrasound-
O hypoechoic round or oval lesions located close to the liver capsuleO show low-level internal echoes and posterior acoustic enhancement
O CT-O slightly higher attenuation than water may have smooth or nodular
bordersO thick (3–15 mm) wall that typically enhances
O MRIO the central portion cystic,O “rind” exhibits variable intensities on T1- and T2-weighted imaging
Amebic Liver Abscess
Hydatid CystO 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 appearancesO simple cyst with no internal architectureO cyst with daughter cysts and a matrixO calcified cystO 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
Hydatid Cyst
Fungal MicroabscessesO typically seen in the immunocompromised populationO small lesions(< 2 cm) and disseminated throughout the
liver and the spleen, sometimes renalO 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 sensitiveO most lesions being detectable on the arterial phase as
uniformly hypoattenuating O MRI
O most conspicuous on the T2O Mimics of hepatosplenic fungal infection include
granulomatous diseases (e.g., sarcoidosis) and rarely aseptic abscesses
Fungal Microabscesses
Intrahepatic pseudocystO extremely rare condition- usually as a complication
of acute alcoholic pancreatitisO affect young and middle-age menO high propensity for the right lobeO 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
Neoplastic Lesions
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 intrahepaticO BCAC is usually a result of malignant transformation of BCA
(risk as high as 20%) but can also arise de novoO imaging findings overlap
O multilocular with enhancing walls, O fine septations, and variable calcificationO can be as large as 30 cmO 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
Biliary Cystadenoma (BCA) and Cystadenocarcinoma (BCAC)
Biliary Cystadenoma (BCA) and Cystadenocarcinoma (BCAC)
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
Cystic Hepatocellular Carcinoma
Cystic Liver MetastasesO 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 contentO rapid growth of the tumor with hemorrhage, necrosis,
or cystic degenerationO cystic degeneration after chemotherapy
O hypoattenuating to background liver on CT ,usually irregular peripheral rim of enhancement
Cystic Liver Metastases
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 featuresO large (> 10 cm) solitary lesion commonly in the right lobeO ultrasound- solid iso to hyperechoic with small anechoic
areas corresponding to areas of necrosis or cystic degeneration
O CTO unenhanced CT-cystic with near-water attenuation: high water
content of its myxoid stromaO Contrast-enhanced CT can show different degrees of
enhancementO MR
O cystic on unenhanced T1- and T2-weighted sequencesO heterogeneous enhancement post contrast -better seen in the
late portal venous phase
Undifferentiated Embryonal Sarcoma
Undifferentiated Embryonal Sarcoma
Trauma-related
Oma-sO Post trauma or iatrogenic injury ,collection of
O bile-biloma, O lymph- seromaO 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 enhancementO 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
Oma-s
Approach
MimicsO 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 SteatosisO nodular steatosis rarely can mimic a
cystic lesion on unenhanced CTO MRI with the use of chemical-shift
gradient-echo imaging
MimicsO Peribiliary Cyst
O obstruction of the neck of the periductal glandsO high association with cirrhosis, portal hypertension,
and AD polycystic diseaseO lesions usually increase in size and number as
cirrhosis and portal hypertension progressO located along the portal tracts in the hilum and
adjacent to the large intrahepatic ductsO 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
Peribiliary Cyst
Thank You…
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