incidental liver lesions

Incidental Liver Lesions Incidental Liver Lesions

Incidental Liver LesionsIncidental Liver Lesions

The widespread use of imaging The widespread use of imaging techniques for abdominal investigation has techniques for abdominal investigation has led to an increased detection of the so-led to an increased detection of the so-called ‘incidental liver lesion’ or called ‘incidental liver lesion’ or incidentaloma.incidentaloma.


An An incidentalomaincidentaloma is a is a tumortumor ( (-oma-oma) found ) found by coincidence (by coincidence (incidentalincidental) without clinical ) without clinical symptomssymptoms or suspicion. It is a benign or suspicion. It is a benign growth, which is detected when growth, which is detected when diagnostic imagingdiagnostic imaging is used for the analysis is used for the analysis of unrelated symptoms.of unrelated symptoms.


It is important to recognize that the range It is important to recognize that the range of diagnoses of diagnoses encounteredencountered will be related to will be related to the population under study. the population under study.

For example: Patients subjected to For example: Patients subjected to imaging studies to investigate benign imaging studies to investigate benign conditions such as cholecystitis or renal conditions such as cholecystitis or renal colic are likely to have findings that mirror colic are likely to have findings that mirror those of the general population.those of the general population.

By contrast, the likelihood of encountering By contrast, the likelihood of encountering malignant hepatic lesions will probably be malignant hepatic lesions will probably be greater in patients diagnosed with cancer and greater in patients diagnosed with cancer and undergoing extent of disease assessment or in undergoing extent of disease assessment or in chronic hepatitis patients undergoing screening chronic hepatitis patients undergoing screening evaluation. evaluation.

Thus, the radiographic findings and the clinical Thus, the radiographic findings and the clinical context must always be considered together to context must always be considered together to formulate an appropriate differential diagnosis.formulate an appropriate differential diagnosis.

Incidental Liver LesionsIncidental Liver Lesions It is important to consider the clinical It is important to consider the clinical

circumstances in which the lesion was identified:circumstances in which the lesion was identified: patient's agepatient's age gendergender use of oral contraceptives, use of oral contraceptives, history or risk factors for chronic liver disease or history or risk factors for chronic liver disease or

cirrhosiscirrhosis history or findings of extrahepatic malignancyhistory or findings of extrahepatic malignancy Is there a travel history or are there other Is there a travel history or are there other

features suggesting an amebic or pyogenic features suggesting an amebic or pyogenic abscess? abscess?

Incidental Liver LesionsIncidental Liver Lesions The size of the liver lesion is an important consideration The size of the liver lesion is an important consideration

in guiding the evaluation:in guiding the evaluation: Lesions smaller than approximately 1.0 cm are Lesions smaller than approximately 1.0 cm are

commonly benign incidental findings on imaging studies, commonly benign incidental findings on imaging studies, and in most cases represent small cysts, hemangiomas, and in most cases represent small cysts, hemangiomas, or biliary hamartomasor biliary hamartomas

they are frequently difficult to definitively characterize by they are frequently difficult to definitively characterize by imaging methods due to their small size, and difficult to imaging methods due to their small size, and difficult to biopsy percutaneously. biopsy percutaneously.

Often clinical follow-up is the only recourse for these Often clinical follow-up is the only recourse for these lesionslesions

Larger lesions can be characterized in most cases as Larger lesions can be characterized in most cases as outlined in this review.outlined in this review.

Simplified flow chart of imaging techniques commonly used to study the incidental liver lesion. MRI plays an increasing role in the characterisation of solid lesions encountered on US or CT images

Hepatic cystsHepatic cysts maybe classified as:maybe classified as:

DevelopmentalDevelopmental InfectiousInfectious TraumaticTraumatic NeoplasticNeoplastic

arise from the bile duct epithelium (cholangiocellular)arise from the bile duct epithelium (cholangiocellular) unilocular unilocular solitary or multiplesolitary or multiple Cyst wall – 1mm or less in thicknessCyst wall – 1mm or less in thickness

lined by a simple layer of cuboidal epitheliumlined by a simple layer of cuboidal epithelium less commonly by squamous or columnar epitheliumless commonly by squamous or columnar epithelium

adjacent liver tissue is normal and free of fibrosis or inflammationadjacent liver tissue is normal and free of fibrosis or inflammation 5 to 14% of the population5 to 14% of the population slightly more prevalent in womenslightly more prevalent in women

Hepatic cystsHepatic cysts

Ultrasound is the best imaging method for Ultrasound is the best imaging method for characterising these purely cystic liver characterising these purely cystic liver lesions:lesions:

Well-defined homogeneous cystic Well-defined homogeneous cystic componentcomponent

Posterior acoustic enhancementPosterior acoustic enhancement Absence of a Doppler signalAbsence of a Doppler signal

Hepatic cystsHepatic cysts

The demonstration of internal or mural solid The demonstration of internal or mural solid components precludes the diagnosis of a simple cyst components precludes the diagnosis of a simple cyst and justifies further imaging investigationsand justifies further imaging investigations

In these cases, the differential diagnosis should include In these cases, the differential diagnosis should include 1.1. cystic malignant tumours, such as the rare cystic malignant tumours, such as the rare

cystadenocarcinoma or a cystic metastasiscystadenocarcinoma or a cystic metastasis2.2. a cystic hydatid lesion (type 1). a cystic hydatid lesion (type 1).

When the criteria for an ultrasonographic diagnosis of a When the criteria for an ultrasonographic diagnosis of a simple cyst are not fulfilled, a spiral CT should be simple cyst are not fulfilled, a spiral CT should be performed. performed.

Simple biliary liver cyst with the absence of a definite wall and lack of enhancement

Precontrast Postcontrst

Simple liver cyst

Cystic NeoplasmCystic Neoplasm

A thickened, irregular, enhancing wall – as well as A thickened, irregular, enhancing wall – as well as internal septa and heterogeneity – favours a cystic internal septa and heterogeneity – favours a cystic neoplasmneoplasm

Presence of symptoms related to the cyst or Presence of symptoms related to the cyst or increasing sizeincreasing size

Cystadenoma Cystadenocarcinoma

Treatment of Hepatic cystsTreatment of Hepatic cysts

Majority do not require treatmentMajority do not require treatment Monitor large cysts (≥4 cm in diameter) Monitor large cysts (≥4 cm in diameter)

periodically with ultrasonography to assure periodically with ultrasonography to assure that they remain stablethat they remain stable

Laparoscopic unroofing curative for simple Laparoscopic unroofing curative for simple cystscysts

Enucleation for a cystadenomaEnucleation for a cystadenoma Formal hepatic resection for Formal hepatic resection for

cystadenocarcinomas. cystadenocarcinomas.

Hydatid cystHydatid cyst

Possess septations, Possess septations, Mural calcificationsMural calcifications Daughter cysts within the parent cystDaughter cysts within the parent cyst

Hepatic HaemangiomaHepatic Haemangioma CAVERNOUS HEMANGIOMA – most common benign CAVERNOUS HEMANGIOMA – most common benign

neoplasm of the liverneoplasm of the liver second most common hepatic tumor, exceeded only by second most common hepatic tumor, exceeded only by

metastasesmetastases affects all age groupsaffects all age groups women > menwomen > men within the right lobe of the liverwithin the right lobe of the liver few millimeters to greater than 20 cm diameterfew millimeters to greater than 20 cm diameter mesodermal in originmesodermal in origin histologically : blood-filled cavernous vascular spaces of histologically : blood-filled cavernous vascular spaces of

variable size and shape lined single layer of flat variable size and shape lined single layer of flat endotheliumendothelium

stable lesions, rarely increase or decrease in sizestable lesions, rarely increase or decrease in size

Hepatic HaemangiomaHepatic Haemangioma

Gross specimen of a hepatic hemangioma. The Gross specimen of a hepatic hemangioma. The cut surface demonstrates a brown to red cut surface demonstrates a brown to red appearance with areas of focal hemorrhage and appearance with areas of focal hemorrhage and fibrosis fibrosis


• Characteristic Characteristic ultrasonographic ultrasonographic features: features: 1. Well-defined, 1. Well-defined, homogeneous, homogeneous, hyperechoic lesionhyperechoic lesion2. Posterior acoustic 2. Posterior acoustic enhancementenhancement3. No signal on colour-3. No signal on colour-

coded Dopplercoded Doppler

Hepatic HaemangiomaHepatic Haemangioma In cases where the US findings are not diagnostic, or where doubts In cases where the US findings are not diagnostic, or where doubts

persist (especially in oncological patients), persist (especially in oncological patients), CT with iodinated CT with iodinated contrast media injectioncontrast media injection is necessary to assess tumour vascularity is necessary to assess tumour vascularity and provides diagnostic tumour enhancement showing:and provides diagnostic tumour enhancement showing:

1. A lesion hypodense to the liver before the injection of iodinated 1. A lesion hypodense to the liver before the injection of iodinated contrast media (similar to that of vessels)contrast media (similar to that of vessels)

2. Patchy globular enhancement in the early phase of contrast media 2. Patchy globular enhancement in the early phase of contrast media administration (arterial phase) beginning at the periphery of the administration (arterial phase) beginning at the periphery of the tumourtumour

3. Progressive centripetal fill-in3. Progressive centripetal fill-in

4. Persistent enhancement on delayed imaging4. Persistent enhancement on delayed imaging

Hepatic Haemangioma Hepatic Haemangioma

The hypodense lesion on the right liverThe hypodense lesion on the right liverlobe shows peripheral enhancement atlobe shows peripheral enhancement atthe early phase of this study.the early phase of this study.

Subsequent hyperdensity (retention) in the late phase

Haemokinetics of liver haemangioma by dynamic CT


Indications of MRI:Indications of MRI: small-sized lesions (<1 cm)small-sized lesions (<1 cm) hypervascular behaviour after contrast hypervascular behaviour after contrast

enhancement (the ‘flash-filling enhancement (the ‘flash-filling haemangioma’)haemangioma’)

in cases of absent or delayed fill-in patternin cases of absent or delayed fill-in pattern


Characteristics of a haemangioma imaged by MRI Characteristics of a haemangioma imaged by MRI include:include:

A homogeneous, well-defined lesion, with lobulated A homogeneous, well-defined lesion, with lobulated contourscontours

Hypointensity on T1-weighted imagesHypointensity on T1-weighted images Strong hyperintensity on heavily T2-weighted imagesStrong hyperintensity on heavily T2-weighted images Typical filling pattern with dynamic imaging, observed Typical filling pattern with dynamic imaging, observed

after intravenous administration of gadolinium after intravenous administration of gadolinium chelateschelates

MRI of a cavernous MRI of a cavernous hemangioma in an hemangioma in an asymptomatic 52-asymptomatic 52-year-old man year-old man


99mTc-RBC pool study demonstrates retention 99mTc-RBC pool study demonstrates retention of radiolabelled tracer in the right lobe of the of radiolabelled tracer in the right lobe of the liver on delayed images consistent with a liver on delayed images consistent with a hepatic hemangioma hepatic hemangioma

Treatment of Hepatic Treatment of Hepatic HaemangiomaHaemangioma

Asymptomatic patients, particularly those with Asymptomatic patients, particularly those with lesions <1.5 cm but including those ≤5 cm, can lesions <1.5 cm but including those ≤5 cm, can be reassured and observedbe reassured and observed

Rapid growth of a hemangioma has been Rapid growth of a hemangioma has been reported, justifying close radiologic follow-up of reported, justifying close radiologic follow-up of patients with lesions >5 cm, particularly those in patients with lesions >5 cm, particularly those in a subcapsular location. In the absence of a subcapsular location. In the absence of symptoms, the risk of bleeding is too low to symptoms, the risk of bleeding is too low to justify prophylactic resectionjustify prophylactic resection

Treatment of Hepatic Treatment of Hepatic HaemangiomaHaemangioma

Patients who have pain or symptoms Patients who have pain or symptoms suggestive of extrinsic compression of suggestive of extrinsic compression of adjacent structures should be considered adjacent structures should be considered for surgical resection (liver resection, for surgical resection (liver resection, enucleation, hepatic artery ligation, and enucleation, hepatic artery ligation, and liver transplantationliver transplantation

Non-surgical techniques (hepatic artery Non-surgical techniques (hepatic artery embolization, radiotherapy, and interferon embolization, radiotherapy, and interferon alpha-2a) mainly in childrenalpha-2a) mainly in children

Focal nodular hyperplasiaFocal nodular hyperplasia

A benign tumour-like lesion (containing a highly A benign tumour-like lesion (containing a highly vascularised central scar), predominantly in young vascularised central scar), predominantly in young femalesfemales

Unlike HA, the association of FNH with oral Unlike HA, the association of FNH with oral contraceptives/estrogens has not been clearly contraceptives/estrogens has not been clearly establishedestablished

No malignant potential and complications are also No malignant potential and complications are also exceedingly rareexceedingly rare

Therefore, adequate diagnosis by non-invasive imaging Therefore, adequate diagnosis by non-invasive imaging techniques avoids unjustified surgical resectiontechniques avoids unjustified surgical resection

However, FNH shares some imaging features with other However, FNH shares some imaging features with other primary liver tumours including some of malignant origin primary liver tumours including some of malignant origin (e.g. adenoma, hepatocellular carcinoma), and thus a (e.g. adenoma, hepatocellular carcinoma), and thus a diagnosis of FNH must be unequivocal diagnosis of FNH must be unequivocal


Surgical specimen Surgical specimen showing a mass showing a mass lesion within a lesion within a noncirrhotic liver.noncirrhotic liver.

Note the central Note the central stellate scar. stellate scar.


An accurate diagnosis of FNH can be An accurate diagnosis of FNH can be made from an ultrasound study showing:made from an ultrasound study showing:

A homogeneous, solid lesion of variable A homogeneous, solid lesion of variable echogenicityechogenicity

Absence of a peripheral hypoechoic rim Absence of a peripheral hypoechoic rim (capsule)(capsule)

Hyperechoic or hypoechoic central scar, Hyperechoic or hypoechoic central scar, displaying arterial vessels within the displaying arterial vessels within the central scar on colour-coded Doppler central scar on colour-coded Doppler

Focal nodular hyperplasiaFocal nodular hyperplasia If in dout, then Dynamic CT or MRIIf in dout, then Dynamic CT or MRI


Arterial phase of a triphasic helical CT scan reveals large Arterial phase of a triphasic helical CT scan reveals large arateries feeding a hyperintense mass in the left lobe of arateries feeding a hyperintense mass in the left lobe of the liver (left panel). A later phase of the same helical CT the liver (left panel). A later phase of the same helical CT

reveals a central, hypointense scar (right panel arrow).reveals a central, hypointense scar (right panel arrow).


The tumour is isointense with the normal liver parenchyma except for the central scar (long arrow) which is (a) hypointense on the T1-weighted MRI image and (b) bright on the T2-weighted image. Incidentally there is a bright lesion on the right liver lobe corresponding to a small haemangioma (short arrow)


Technetium sulfur Technetium sulfur colloid scan shows colloid scan shows uniform uptake uniform uptake indicating that the indicating that the FNH mass has FNH mass has Kupffer cellsKupffer cells


If any of the features of FNH are lacking from CT If any of the features of FNH are lacking from CT or MRI images, a confident diagnosis is or MRI images, a confident diagnosis is precluded and patients must undergo a more precluded and patients must undergo a more invasive diagnostic procedure, preferably a invasive diagnostic procedure, preferably a surgical biopsysurgical biopsy. Image-guided percutaneous . Image-guided percutaneous biopsies can be inconclusive since they may not biopsies can be inconclusive since they may not represent the overall histology of the tumour.represent the overall histology of the tumour.

Surgical removal remains the treatment of Surgical removal remains the treatment of choice in the case of an atypical diagnosis of choice in the case of an atypical diagnosis of FNH.FNH.

Treatment of FNHTreatment of FNH

The natural history of FNH is one of The natural history of FNH is one of stability and lack of complicationsstability and lack of complications

Surgery for:Surgery for: rare, very symptomatic FNH lesionrare, very symptomatic FNH lesion highly suspicious lesion, which has eluded highly suspicious lesion, which has eluded

diagnosis by all other modalitiesdiagnosis by all other modalities

Hepatic adenomaHepatic adenoma

Benign tumour of hepatocellular originBenign tumour of hepatocellular origin Exceedingly rare compared with the previously described Exceedingly rare compared with the previously described

lesionslesions Most commonly seen in premenopausal women older Most commonly seen in premenopausal women older

than 30 than 30 Generally related to long-term use of contraceptive pills Generally related to long-term use of contraceptive pills

or the use of sex steroidsor the use of sex steroids Has a high propensity to bleed, rupture and may Has a high propensity to bleed, rupture and may

undergo malignant transformation. Therefore, it should undergo malignant transformation. Therefore, it should generally be resected generally be resected

Can be difficult to distinguish from an extremely well-Can be difficult to distinguish from an extremely well-differentiated hepatocellular carcinomadifferentiated hepatocellular carcinoma


Gross sectioned pathological specimen of a resected Gross sectioned pathological specimen of a resected pedunculated hepatic adenoma measuring >6 cm in pedunculated hepatic adenoma measuring >6 cm in diameter. The adenoma shows the typically tan fleshy diameter. The adenoma shows the typically tan fleshy appearance of an adenoma with no capsule. There is no appearance of an adenoma with no capsule. There is no evidence of hemorrhage or necrosis evidence of hemorrhage or necrosis


Diagnosis is based upon clinical setting, a Diagnosis is based upon clinical setting, a combination of imaging studies, and/or combination of imaging studies, and/or surgical resection surgical resection

A biopsy or aspirate is generally not A biopsy or aspirate is generally not recommended because HAs are recommended because HAs are associated with increased risk of bleeding associated with increased risk of bleeding & a needle biopsy is often nondiagnostic& a needle biopsy is often nondiagnostic

A common dilemma is the differentiation of A common dilemma is the differentiation of a HA from focal nodular hyperplasiaa HA from focal nodular hyperplasia


Ultrasonography: nonspecificUltrasonography: nonspecific often large and in the right lobe of the liveroften large and in the right lobe of the liver usually hyperechoic in relation to the usually hyperechoic in relation to the

surrounding liver parenchymasurrounding liver parenchyma Given the tendency for these lesions to bleed, Given the tendency for these lesions to bleed,

there is often a central hypoechoic region, which there is often a central hypoechoic region, which corresponds to hemorrhagecorresponds to hemorrhage

Contrast enhanced ultrasonography may Contrast enhanced ultrasonography may improve accuracy compared with standard improve accuracy compared with standard ultrasonographyultrasonography


A CT scan of the liver demonstrates two A CT scan of the liver demonstrates two complex masses in the liver. Adenomas are complex masses in the liver. Adenomas are usually solitary tumors. Multiple adenomas are usually solitary tumors. Multiple adenomas are commonly present in patients with glycogen commonly present in patients with glycogen storage disease. storage disease.


This contrast enhanced CT scan demonstrates a large This contrast enhanced CT scan demonstrates a large complex enhancing mass (X) in the left lobe of the liver complex enhancing mass (X) in the left lobe of the liver displacing vessels (small arrowheads). A smaller, low displacing vessels (small arrowheads). A smaller, low attenuation mass is also noted in the right lobe of the attenuation mass is also noted in the right lobe of the right lobe of the liver (arrow). right lobe of the liver (arrow).


This gadolinum enhanced MRI of the liver acquired during the This gadolinum enhanced MRI of the liver acquired during the early bolus phase of contrast administration demonstrates early bolus phase of contrast administration demonstrates two enhancing masses in the liver, one in the left lateral two enhancing masses in the liver, one in the left lateral segment, the second immediately anterior to the right portal segment, the second immediately anterior to the right portal vein (arrows). The enhancement characterisitcis are non-vein (arrows). The enhancement characterisitcis are non-specific and are seen with any vascular tumor of the liver. specific and are seen with any vascular tumor of the liver.

Hepatic adenomaHepatic adenoma Technetium-99m (99mTc) sulfur colloid scanningTechnetium-99m (99mTc) sulfur colloid scanning:: Most adenomas do not take up the sulfur colloid; thus Most adenomas do not take up the sulfur colloid; thus

the scintigram shows a "cold" spot in the liverthe scintigram shows a "cold" spot in the liver Focal nodular hyperplasia, on the other hand, shows Focal nodular hyperplasia, on the other hand, shows

equal or greater uptake of the radiolabeled agent equal or greater uptake of the radiolabeled agent compared to surrounding liver. compared to surrounding liver.

Thus, sulfur colloid scanning is generally not useful for Thus, sulfur colloid scanning is generally not useful for establishing the diagnosis of an adenoma, but may be establishing the diagnosis of an adenoma, but may be helpful when the clinical setting and results of other helpful when the clinical setting and results of other radiologic testing point to a diagnosis of FNH. radiologic testing point to a diagnosis of FNH.

In many centers, nuclear imaging has been largely In many centers, nuclear imaging has been largely replaced by Gd-BOPTA-enhanced MRI or dynamic multi-replaced by Gd-BOPTA-enhanced MRI or dynamic multi-phase CT angiography. phase CT angiography.

Hepatic adenomaHepatic adenoma The natural history and prognosis of hepatic The natural history and prognosis of hepatic

adenomas is not well established. As a result, adenomas is not well established. As a result, decisions regarding management of these decisions regarding management of these tumors depend upon symptoms, size, number, tumors depend upon symptoms, size, number, location, and certainty of the diagnosis location, and certainty of the diagnosis

Recommend resection of all symptomatic Recommend resection of all symptomatic hepatic adenomas and those with adenomas >5 hepatic adenomas and those with adenomas >5 cm and before pregnancycm and before pregnancy

Adenomas that do not resolve or enlarge after Adenomas that do not resolve or enlarge after discontinuation of steroid medication should also discontinuation of steroid medication should also be considered for surgical resection after be considered for surgical resection after discussion with the patient. discussion with the patient.

Malignant liver TumorsMalignant liver Tumors

More common than benign lesions and are More common than benign lesions and are associated with a poorer outcomeassociated with a poorer outcome

Thus, it is important to establish a correct Thus, it is important to establish a correct diagnosis, especially when the potential diagnosis, especially when the potential for therapy exists.for therapy exists.

Metastatic Liver TumoursMetastatic Liver Tumours In Western countries, metastatic liver tumors are the most In Western countries, metastatic liver tumors are the most

common malignant hepatic neoplasmcommon malignant hepatic neoplasm The presence of an extrahepatic malignancy should be sought The presence of an extrahepatic malignancy should be sought

in patients with characteristic liver lesions on imaging studiesin patients with characteristic liver lesions on imaging studies A thorough physical examination and history should be A thorough physical examination and history should be

performed to identify clues to the primary malignancy. performed to identify clues to the primary malignancy. In patients known to have an extrahepatic malignancy, it is In patients known to have an extrahepatic malignancy, it is

usually necessary to clarify if a hepatic lesion might be usually necessary to clarify if a hepatic lesion might be metastatic in origin, because then it typically requires a biopsy.metastatic in origin, because then it typically requires a biopsy.

Ultrasound or CT guided liver biopsy or fine needle aspiration is Ultrasound or CT guided liver biopsy or fine needle aspiration is often useful to confirm the diagnosisoften useful to confirm the diagnosis

However, histologic confirmation is not always essential if However, histologic confirmation is not always essential if reasonable certainty can be achieved with imaging studies or in reasonable certainty can be achieved with imaging studies or in settings in which there would be little benefit to the patient to settings in which there would be little benefit to the patient to establish a firm diagnosis.establish a firm diagnosis.

Metastatic Liver TumoursMetastatic Liver Tumours Ultrasound — Ultrasound findings in metastatic liver Ultrasound — Ultrasound findings in metastatic liver

tumors are variabletumors are variable Metastases from adenocarcinoma are multiple and Metastases from adenocarcinoma are multiple and

hypoechoic in comparison to the surrounding liver hypoechoic in comparison to the surrounding liver parenchyma parenchyma

Transabdominal ultrasonography is inferior in sensitivity Transabdominal ultrasonography is inferior in sensitivity for liver metastases compared to either CT or MRI. It for liver metastases compared to either CT or MRI. It should not be relied upon when imaging smaller lesions should not be relied upon when imaging smaller lesions is necessary is necessary

Intraoperative ultrasonography is the most sensitive Intraoperative ultrasonography is the most sensitive imaging technique for diagnosing liver metastases and imaging technique for diagnosing liver metastases and can be helpful in delineating the extent of disease and can be helpful in delineating the extent of disease and vascular landmarks during hepatic resectionvascular landmarks during hepatic resection

Metastatic Liver TumoursMetastatic Liver Tumours

Triphasic CT:Triphasic CT: metastatic liver lesions from the metastatic liver lesions from the colon, colon,

stomach, and pancreasstomach, and pancreas usually show lower usually show lower attenuation (ie, are darker) in contrast to the attenuation (ie, are darker) in contrast to the brighter surrounding liver parenchymabrighter surrounding liver parenchyma

Hypervascular metastases, such as those from Hypervascular metastases, such as those from neuroendocrine tumors, renal cell carcinoma, neuroendocrine tumors, renal cell carcinoma, breast carcinoma, melanoma, and thyroid breast carcinoma, melanoma, and thyroid carcinomacarcinoma, appear as rapidly enhancing lesions , appear as rapidly enhancing lesions visible on the arterial phase of enhancement.visible on the arterial phase of enhancement.


A contrast-enhanced CT scan of the liver A contrast-enhanced CT scan of the liver demonstrates multiple hypovascular metastases demonstrates multiple hypovascular metastases throughout all lobes of the liver. These lesions throughout all lobes of the liver. These lesions are typical of metastatic colon cancer. Ascites is are typical of metastatic colon cancer. Ascites is also presentalso present


MRI is useful for delineating vascular MRI is useful for delineating vascular involvement and identifying additional involvement and identifying additional intraabdominal lesionsintraabdominal lesions

Specialized contrast agents, such as Specialized contrast agents, such as superparamagnetic iron oxide agents, improve superparamagnetic iron oxide agents, improve the sensitivity of MRI for metastasesthe sensitivity of MRI for metastases

However, intraoperative ultrasound is still more However, intraoperative ultrasound is still more sensitive for the detection of liver metastasessensitive for the detection of liver metastases


Resectable CRC liver metastases are defined Resectable CRC liver metastases are defined simply as tumors that can be resected simply as tumors that can be resected completely, leaving an adequate liver remnantcompletely, leaving an adequate liver remnant

Most surgeons would require that there be no Most surgeons would require that there be no radiographic evidence of involvement of the radiographic evidence of involvement of the hepatic artery, major bile ducts, main portal vein, hepatic artery, major bile ducts, main portal vein, or celiac/paraaortic lymph nodes and adequate or celiac/paraaortic lymph nodes and adequate predicted functional hepatic reserve predicted functional hepatic reserve postresection. postresection.

Hepatocellular carcinomaHepatocellular carcinoma Hx risk factors for chronic liver disease viral hepatitis, Hx risk factors for chronic liver disease viral hepatitis,

metabolic liver diseases such as hereditary metabolic liver diseases such as hereditary hemochromatosis, and alcohol abusehemochromatosis, and alcohol abuse

• Physical examination: peripheral stigmata of cirrhosis or Physical examination: peripheral stigmata of cirrhosis or decompensated liver disease, which should raise decompensated liver disease, which should raise suspicion for HCCsuspicion for HCC

• The diagnosis can be difficult, and often requires the use The diagnosis can be difficult, and often requires the use of serum markers, one or more imaging modalities, and of serum markers, one or more imaging modalities, and histologic confirmationhistologic confirmation

• As a result, many patients have untreatable disease As a result, many patients have untreatable disease when first diagnosed.when first diagnosed.

Hepatocellular carcinomaHepatocellular carcinoma

• The median survival following diagnosis is The median survival following diagnosis is approximately 6 to 20 monthsapproximately 6 to 20 months

• Large tumor size, vascular invasion, poor Large tumor size, vascular invasion, poor functional status, and nodal metastases functional status, and nodal metastases are all associated with a poor outcomeare all associated with a poor outcome

• HCC is frequently diagnosed late in its HCC is frequently diagnosed late in its course because of the absence of course because of the absence of pathognomonic symptoms and the liver's pathognomonic symptoms and the liver's large functional reservelarge functional reserve


• It can be challenging to distinguish HCC It can be challenging to distinguish HCC from regenerative or even dysplastic from regenerative or even dysplastic nodules in patients with cirrhosisnodules in patients with cirrhosis

• MRI is currently the modality of choice in MRI is currently the modality of choice in such settings since distinctions can such settings since distinctions can sometimes be made based upon the sometimes be made based upon the enhancement pattern and the presence of enhancement pattern and the presence of iron in regenerative nodulesiron in regenerative nodules

Hepatocellular carcinomaHepatocellular carcinoma Serum AFP is normal in the majority of patients Serum AFP is normal in the majority of patients

with the fibrolamellar HCC and in up to 40 with the fibrolamellar HCC and in up to 40 percent of patients with HCC. Some authorities percent of patients with HCC. Some authorities recommend a biopsy; however, the risk of recommend a biopsy; however, the risk of malignant seeding of the biopsy tract in patients malignant seeding of the biopsy tract in patients who turn out to have an HCC is about 5 percent. who turn out to have an HCC is about 5 percent. Thus, in good surgical candidates in whom HCC Thus, in good surgical candidates in whom HCC cannot be excluded, resection may be the best cannot be excluded, resection may be the best course of action.course of action.

A central scar (typical of focal nodular A central scar (typical of focal nodular hyperplasia) can also be seen in patients with hyperplasia) can also be seen in patients with fibrolamellar HCC.fibrolamellar HCC.


A contrast-enhanced CT scan demonstrates a A contrast-enhanced CT scan demonstrates a hepatoma (arrow) in the dome of the liver which hepatoma (arrow) in the dome of the liver which is invading the vena cava (arrowhead)is invading the vena cava (arrowhead)


MRI of the liver performed in a 73-year-old man with hepatitis C and MRI of the liver performed in a 73-year-old man with hepatitis C and cirrhosis, and a newly diagnosed hepatocellular cancercirrhosis, and a newly diagnosed hepatocellular cancer

Panel A: tumor is slightly hyperintense, with a thin low-signal Panel A: tumor is slightly hyperintense, with a thin low-signal intensity capsule (arrow)intensity capsule (arrow)

Panel B: shows the low signal intensity of the tumor relative to Panel B: shows the low signal intensity of the tumor relative to adjacent liver, and the capsule is enhancing (arrow). adjacent liver, and the capsule is enhancing (arrow).

Treatment algorithm for hepatocellular carcinoma

PVE: Portal vein embolization; RFA: Radiofrequency ablation; PEI: Percutaneous ethanol injection; TACE: Transcatheter arterial chemoembolization.* Suitability of patients with Child-Pugh B cirrhosis for surgical resection is highly controversial.• If not a liver transplantation candidate because disease is outside transplant (Milan) criteria, downstaging therapy (RFA, TACE) could be considered, followed by reassessment for liver transplantation.Δ Systemic therapy options include participation in a clinical trial (preferred) or sorafenib.

The ‘sub-centimetre’ liver lesionThe ‘sub-centimetre’ liver lesion With increased resolution of CT and MRI has With increased resolution of CT and MRI has

come an increased detection of small nodules: come an increased detection of small nodules: 17% of patients with or without known previous 17% of patients with or without known previous malignancies may display small liver nodules malignancies may display small liver nodules ≤≤10 mm in diameter which are difficult or even 10 mm in diameter which are difficult or even impossible to characterise adequatelyimpossible to characterise adequately

The majority of these small lesions are benign, The majority of these small lesions are benign, such as tiny liver cysts or hamartomas, but they such as tiny liver cysts or hamartomas, but they can also be malignantcan also be malignant

High-resolution, state-of-the-art US techniques High-resolution, state-of-the-art US techniques can be diagnostic for sub-centimetre cystic can be diagnostic for sub-centimetre cystic nodulesnodules

The ‘sub-centimetre’ liver lesionThe ‘sub-centimetre’ liver lesion

small solid nodules are generally invisible in small solid nodules are generally invisible in most US examinationsmost US examinations

The small solid nodules are being increasingly The small solid nodules are being increasingly recognised in good-quality spiral CT studiesrecognised in good-quality spiral CT studies

it is advisable to obtain a new control it is advisable to obtain a new control examination after about 3–4 months. Any examination after about 3–4 months. Any intervening growth may justify the use of another intervening growth may justify the use of another diagnostic procedure, such as an image-guided diagnostic procedure, such as an image-guided percutaneous biopsypercutaneous biopsy

Sub-centimetre lesion showing interval growth. Sub-centimetre lesion showing interval growth. This patient was screened for metastases from a This patient was screened for metastases from a colorectal cancer.colorectal cancer.

(a) A tiny hypodense nodule is indicated by the arrow.

(b) Characterisation was not possible, but a control CT scan performed 4 months later showed clear enlargement. The final diagnosis was a hepatic metastasis.

ConclusionsConclusions Current imaging techniques can accurately characterise Current imaging techniques can accurately characterise

incidental liver lesions in a non-invasive fashion.incidental liver lesions in a non-invasive fashion. Ultrasound is used as a primary screening modality, but Ultrasound is used as a primary screening modality, but

in several instances, CT or MRI act as the ‘problem-in several instances, CT or MRI act as the ‘problem-solving’ technique. solving’ technique.

Magnetic resonance imaging is superior to helical CT for Magnetic resonance imaging is superior to helical CT for focal liver lesion characterisation as a result of its high focal liver lesion characterisation as a result of its high intrinsic contrast resolution and potential use of different intrinsic contrast resolution and potential use of different types of contrast agents, both specific and non-specific.types of contrast agents, both specific and non-specific.

Sub-centimetre nodules continue to be a diagnostic Sub-centimetre nodules continue to be a diagnostic dilemma demanding a close-imaging examination, which dilemma demanding a close-imaging examination, which depends largely on the clinical situation of the patient. depends largely on the clinical situation of the patient.

References:References: How to characterise the incidental liver lesion, How to characterise the incidental liver lesion,

http://www.c2i2.org/winter2003/How%20to%20chttp://www.c2i2.org/winter2003/How%20to%20characterise%20the%20incidental%20liver%20leharacterise%20the%20incidental%20liver%20lesion.aspsion.asp

2011 UpToDate2011 UpToDate Incidentally Discovered Hepatic Lesions. Incidentally Discovered Hepatic Lesions.

RONALD S. CHAMBERLAIN, MD, RONALD S. CHAMBERLAIN, MD, MPA,WILLIAM R. JARNAGIN, MD,DOUGLAS MPA,WILLIAM R. JARNAGIN, MD,DOUGLAS DECORATO, MDDECORATO, MD

incidental liver lesions

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