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Primary and secondary liver tumours

 

§       benign and malignant tumours may arise in liver

·       from hepatocytes

·       bile-duct epithelium

·       supporting mesenchymal tissue

§       except HCC, all primary malignant tumours of liver ® rare

§       but liver is frequently site of metastatic deposits

 

Hepatocellular carcinoma

Cholangiosarcoma

Angiosarcoma (Kupffer-cell sarcoma)

Epithelioid haemangioendothelioma

Other primary malignant tumours

Hepatic metastases

Benign tumours

 

Hepatocellular carcinoma

o      epidemiology

o      aetiology

o      clinical features

o      investigations

o      screening

o      prognosis

o      treatment

 

§       occurs either as

·       single mass, or

·       scattered nodules of tumour

§       pre-existing cirrhosis in » 80% of patients

§       tumour tends to invade portal and hepatic veins

§       spreads to

·       abdominal lymph nodes

·       bone

§       histologically, tumour typically composed of cells resembling hepatocytes

·       arranged in cords

§       other distinct histological subtypes recognized

·       including fibrolamellar variant

o     clumps of eosinophilic carcinoma cells, surrounded by characteristic fibrous stroma

o     occurs in young-adults in a non-cirrhotic liver

Epidemiology

 

·       comparatively rare tumour in Western Europe and North America

o      annual incidence in these areas » 1-2 per 100,000

o      recent evidence suggests it is becoming more common

·       incidence 20-30 times higher

·       in patients with underlying cirrhosis

o      males greatly outnumber females

·       in non-cirrhotic cases

o      sex difference less striking

·       in areas of high incidence

o      peak age – 3rd and 4th decades

·       in Europe and North America

o      most cases occur in 5th and 6th decades

 

Aetiology

 

§       cirrhosis, particularly macronodular form, present in » 80% of cases.

§       in Western Europe and United States, usually due to

·       chronic alcoholism

·       chronic hep B/C

§       in Africa and Asia, chronic liver disease usually associated with

·       Hep B/C virus infection

§       rare cases

·       complicate cirrhosis due to other causes

·       may follow

o     prolonged use of oral contraceptive pill

o     prior investigations using radioactive contrast agent Thorotrast

§       in parts of Africa and Far East

·       increasing evidence implicating aflatoxin

o     potent carcinogen derived from Aspergillus flavus

§       a mould which often contaminates food

§       Hep B virus recognized to have an important role in development of hepatocellular carcinoma

·       particularly in areas of high incidence

·       risk of developing HCC in HBV carriers is at least 100 times higher than in matched uninfected controls

·       HBV can be identified in

o     tumour, as well as

o     surrounding liver

·       integration of viral DNA in genome of HCC has been shown

o     may result in

§       major structural rearrangements in adjacent cellular DNA

§       deletions, duplications and translocations have been reported

·       in geographical areas with high HBV endemicity as well as exposure to aflatoxins

o     one of a variety of mutations of p53 on chromosome 17 is a frequent finding

o     mechanism of initiation and progress of these molecular events unclear

§       Hep C virus also closely linked with HCC development

·       especially in North America, Western Europe and Japan

o     areas where HBV is not hyperendemic

·       almost all cases associated with cirrhosis

·       latent period may be as long as 25-30 years post-infection

§       HCC is largely preventable

·       in Taiwan extensive use of HBV vaccination has led to reduced incidence

·       until HCV vaccination is available, measures must be taken to reduce transmission

·       there are indications that successful treatment of chronic Hep B and C will reduce cancer risk

 

Clinical features

 

·       In Africa and other high-incidence areas,

o      a short history of right upper abdominal pain

o      often associated with

§       fever

§       weight loss

o      may be considerable abdominal swelling

§       due to liver enlargement

§       with or without ascites

o      catastrophic intraperitoneal bleeding sometimes,

§       due to tumour rupture.

 

·       In low-incidence areas

o      disease is often more insidious

o      general deterioration in health of a patient known to have cirrhosis

o      usually hepatomegaly

o      bruit may be heard over the liver

o      non-metastatic systemic manifestations (rare):

§       hypogycaemia

§       hypercalcaemia

§       porphyria cutanea tarda

 

·       Because of screening in high-risk groups,

o      more small (less than 3 cm in diameter), asymptomatic tumours are now being detected.

 

Investigations

 

·       Haematological and biochemical indices

o      non-specific (apart from a-foetoprotein)

o      reflect the

§       space-occupying lesion

§       underlying cirrhosis (present in about 80% of cases)

o      a-foetoprotein

§       glycoprotein

§       synthesised by foetal liver

§       plasma concn maximum at end of first trimester (3-4 mg/ml), then decline

§       after birth, concentrations fall rapidly to adult levels (1-10 ng/ml)

§       levels

·       raised in 80% of hepatocellular carcinoma patients

·       tend to be higher in African and Far Eastern patients

·       than those in low-incidence areas and those with small tumours

§       concentrations > 500 ng/ml in a patient with liver disease ® highly suggestive of hepatocellular carcinoma

§       sequential readings of great diagnostic value

·       high plasma levels also found

o      in some patients with germinal-cell tumours of

§       testis

§       ovary

o      in occasional patients (usually with hepatic metastases) with carcinoma of

§       stomach

§       pancreas

·       below 500 ng/ml

o      diagnostic “grey zone”

o      such levels may be found in

§       severe viral hepatitis

§       active cirrhosis

·       but subsequent readings tend to fall towards normal in patients with these conditions

·       measurement of hepatoma specific isoforms may improve specificity and sensitivity

o      other tumour markers have been described

§       abnormal vitamin B12 binding protein (usually present in fibrolamellar histological variant)

 

·       liver imaging

o      real-time ultrasound

§       sensitive

§       specific

§       picks up hepatocellular carcinoma in 85-90% of cases

§       false negatives usually with tumours < 2 cm in diameter

o      Abdominal computed tomographic scanning

§       no more accurate than US

§       reserved for cases in which doubt persists

§       sensitivity increased by contrast enhancement

§       dynamic spiral contrast-enhanced CT scanning even more sensitive

o      magnetic resonance imaging

§       useful in identifying and characterising focal liver masses

o      hepatic arteriography

§       excellent visualisation can be obtained

§       major vascular supply to HCC usually arterial

·       therefore diagnostic changes seen in high proportion of cases

§       information on anatomical distribution of the tumour, vascular anatomy

·       essential if surgical resection/transplantation being contemplated

·       intra-arterial chemotherapy, hepatic artery embolisation can be considered

§       sensitivity can be increased by

·       combining it with dynamic spiral CT scanning together with late films to portal venous system

·       injection of iodine-containing contrast medium Lipiodol

o      CT scanning 10-14 days later can visualise Lipiodol selectively retained in tumours

·       liver biopsy

o      essential for definitive diagnosis

§       has not always been possible because of prolongation of prothrombin time

§       diagnosis can be regarded highly likely without liver biopsy proof if

·       a-fetoprotein > 500 ng/ml, and

·       hepatic arteriogram shows a tumour circulation

o      biopsy may be conveniently done at time of laparoscopy or US

§       suspicious areas can be sampled directly under vision

o      risk of tumour spread

§       biopsy often avoided if curative resection/transplantation planned

 

Screening

·       consider for regular screening patients with increased risk of developing HCC

o      cirrhosis

o      chronic Hep B/C infection

·       a-fetoprotein

·       abdominal ultrasonography

·       strategy has been shown

o      to pick up early tumours

o      evidence for improved survival figures for patients in Far East

·       benefits of screening disappointing in Europe

 

Treatment

 

·       curative

o      only complete resection or orthoptic transplantation hold chance of cure

o      consider in every case

o      resection

§       only possible in » 10% of cases

·       underlying cirrhosis

·       or tumour in both lobes

§       often major resection needed

§       in presence of cirrhosis, only limited resection possible

·       liver regeneration defective

·       but procedure may be curative if tumour is small

·       in China, screening programmes to detect early HCC have led to

o      higher rates of tumour resection in cirrhotic patients

o      improved long-term survival figures

§       best results achieved with

·       well-compensated cirrhosis

·       small tumours (less than 3 cm)

§       5-year survival – only 20-30%, due to

·       progression of underlying liver disease

·       tumour recurrence

·       development of new tumours

o      transplantation

§       attractive option for those with cirrhosis and hepatocellular carcinoma

§       procedure can cure both tumour and underlying cirrhosis

§       long-term results best for tumours less than 5 cm in diameter

·       5-year survival – up to 70%

§       best results obtained when

·       HCC discovered incidentally in resected liver when transplantation performed for liver failure

·       fibrolamellar histological variant

·              Palliation

o      radiotherapy

§       external-beam X-irradiation does not produce consistent improvement

§       some encouraging results with intra-arterial Lipiodol mixed with I-131

o      cytotoxic drugs

§       doxorubicin

·       one of few drugs that may produce worthwhile regression

·       only 20-30% of cases respond

·       no survival benefit established

§       hormone receptors present in hepatocytes

·       has prompted attempts to modify tumour growth

·       results poor with tamoxifen

·       octreotide reported to be of value

·              targeted therapies

o      wide variety developed and assessed in recent years

o      very few submitted to prospective randomised controlled trial

o      percutaneous ethanol injection

§       alcohol injected directly into tumour under US guidance

§       causes tumour necrosis

§       repeated injections may be given into more than one tumour mass

§       best results with tumours less than 3 cm in diameter

§       survival figures comparable with limited surgical resection

o      Lipiodol-targeted chemotherapy

§       cytotoxic drugs may be emulsified with Lipiodol

§       delivered directly into liver at selective hepatic arteriography

§       some data show that duration of action of drugs is prolonged because of retention of Lipiodol in tumour

§       however, no convincing evidence of benefit

o      transcatheter arterial embolisation

§       embolisation with foreign materials, e.g. gel foam, can be done at time of hepatic arteriography

§       may result in substantial tumour necrosis

·       particularly in highly vascular tumours

·       which derive bulk of blood supply from hepatic artery

§       contraindicated in patients with

·       decompensated cirrhosis

·       portal vein occlusion

§       broad spectrum antibiotics given for some days

·       risk of anaerobic infection in ischaemic liver

§       tumour necrosis is never complete

·       combine embolisation with targeted chemotherapy ­– chemoembolisation

o            gel foam particles may be soaked in doxorubicin/cisplatin

o            TAE may be immediately preceded by Lipiodol targeted chemotherapy

o            treatment may result in

§       tumour necrosis,

§       shrinkage,

§       symptomatic improvement

o            but three consecutive trials have not established survival benefit

o      cryoablation and thermal ablation

§       intended to destroy tumour cells by physical means

§       no controlled trials have been reported

§       cryotherapy

·       probes inserted into tumour at laparotomy or laparoscopy

·       liquid nitrogen circulated

§       thermal energy

·       applied via probes placed percutaneously in tumour

o      using laser,

o      radiofrequency, or

o      microwaves

·       all three techniques safe

·       few side-effects

·       can be repeated

·       current data insufficient for comparison of efficacy of these techniques

 

Cholangiosarcoma

 

o      epidemiology

o      aetiology

o      signs and symptoms

o      diagnosis

o      prognosis

o      treatment

 

Epidemiology

 

·       much less common than HCC

o      accounts for about 7-10% of primary malignant tumours, except

§              in the Far East, where it makes up » 20%

o      peak age – 6th and 7th decades

o      sex incidence – only slight male predominance

 

Aetiology

 

·       Thorium dioxide (Thorotrast) –

o      well-recognised, but rare cause of intrahepatic variety

·       in Far East

o      infestation of distomes such as Clonorchis sinensis, Opisthorchis viverrini commonly related

·       with long-standing ulcerative colitis

o      risk of biliary-tree carcinoma » 10 ´ risk for general population

·       primary sclerosing cholangitis, and various types of cystic disease of the biliary tree

o      may all be complicated by the development of malignant change

·       unlike HCC, cholangiosarcoma does not appear to be predisposed to by

o      HBV/HCV infection, or

o      or cirrhosis

 

Signs and symptoms

 

·       peripheral intrahepatic type

o      upper abdominal pain

o      anorexia

o      malaise

o      weight loss

·       hilar tumours

o      jaundice – early feature

·       Hepatomegaly – usual

·       Splenomegaly may be found if

o      secondary biliary cirrhosis develops

§       owing to prolonged biliary obstruction

 

Diagnosis

 

·       LFT

o      cholestatic features – elevation of

§       bilirubin

§       alkaline phosphatase levels

·       a-foetoprotein concn

o      usually normal,

§       or only slightly raised

·       Ca and carcinoembryonic antigen levels may also be raised

o      although sensitivity and specificity do not approach 100%

§       raised levels found in obstructive jaundice due to other causes

·       ultrasonography/CT scanning demonstrate tumour mass

·       with hilar tumours

o      show dilatation of the intrahepatic biliary tree

·       hepatic angiography

o      tumour tends to be avascular

o      but encasement and occlusion of vessels occurs

·       biliary tree obstruction in the hilum may be demonstrated – prior to insertion of stent –

o      by MRI cholangiography, or

o      endoscopic retrograde cholangiography (ERCP)

 

Prognosis

 

·       most patients deteriorate progressively

·       average  survival from diagnosis – 12-18 months

·       if biliary drainage can be achieved with hilar tumours

o      prognosis better

§       these tumours often slow-growing

 

Treatment

 

·       for peripheral tumours, same principles of treatment as HCC

·       response to therapy disappointing

·       hilar tumours

o      sometimes suitable for curative resection

§       with anastomosis of Roux loop of jejunum to biliary tree in hilum

o      more usually,

§       curative resection not possible

§       aim is to establish biliary drainage

o      stent can be placed through growth

§       at laparotomy

§       at ERCP

§       or via percutaneous transhepatic route – thus avoiding surgery

§       recent advance – use of self-expanding metal stents

·       useful symptomatic relief may be obtained using

o      conventional radiotherapy

o      high-dose local irradiation within biliary tree with iridium-192 wire

·       if biliary drainage can be achieved using these procedures

o      survival for 1-2 years not unusual

·       liver transplantation seldom indicated

o      because of high risk of tumour recurrence

 

Angiosarcoma (Kupffer-cell sarcoma) – highly malignant

 

·       rare tumour

o      consists of spindle-shaped malignant endothelial cells

·       often multifocal

·       may arise in a cirrhotic liver

·       occurs in patients exposed to Thorotrast 15-25 years earlier

·       chronic exposure to arsenic also implicated

·       has been found in workers in the vinyl chloride industry

o      since this discovery, strict safety regulations introduced, but

o      long latent period,

§       therefore new cases continue to present

·       a few cases in long-term androgen users

o      no aetiological factor yet identified in majority of cases

·       patients present with

o      abdominal pain

o      hepatic enlargement

o      blood-stained ascites common

·       highly malignant tumour

o      curative resection rarely possible

o      no form of palliative treatment has proved effective so far

 

Epithelioid haemangioendothelioma

 

·       malignant tumour

o     rare

·       origin: vascular endothelium

o     characteristic histological appearance

·       usually multifocal

·       occurs in younger patients than angiosarcoma

o      does not have same aetiological associations

·       usually slow-growing

·       prolonged survival reported after

o      resection

o      liver transplantation

 

 

Other primary malignant tumours

 

·       extremely rare, include

o      fibrosarcoma

o      leiomyosarcoma

o      lymphoma

·       children develop both

o      hepatoblastoma

o      HCC

 

Hepatic metastases

 

·       liver – favoured site for metastatic spread

·       » 50% of malignant tumours in portal venous drainage eventually give rise to hepatic metastases

 

o     diagnosis

o     prognosis

o     treatment

 

Diagnosis

·       easy when physical examination reveals a large nodular liver

·       detection of small/solitary deposits difficult

·       LFT’s may be normal

o      but alkaline phosphatase usually rises as tumour mass enlarges

·       US scanning should pick up tumours greater than 1 cm in diameter,

·       but accuracy is greatest when metastases large or numerous

·       targeted liver biopsy at laparoscopy or ultrasonography to confirm diagnosis

 

Prognosis

 

·       worse when there is extensive liver replacement by tumour

o      severe disturbance in liver function tests or ascites

·       site of primary growth also relevant

o      deposits from colorectal cancer – better prognosis than most other tumours

§       untreated mean survival 9-12 months

 

Treatment

 

·       same range of possible treatments as for HCC

·       partial hepatectomy to remove deposits may occasionally lead to prolonged survival or cure

·       special situation with respect to hepatic metastases from carcinoid tumour

o      slow-growing neoplasm

o      main problem is distress caused by flushing and diarrhoea

·       embolisation, or, resection of tumour bulk with no attempt at total removal – often symptomatic relief for some years

·       consider transplantation for slow-growing tumours

·       choice of chemotherapy determined by origin of primary tumour

·       intra-arterial infusion with implantable pumps may give improved quality of life with objective tumour regression

o      but little convincing evidence that survival is prolonged

 

Benign tumours

 

o      haemangioma

o      hepatic adenoma

o      focal nodular hyperplasia

o      other benign tumours

 

Haemangioma

 

·       Most common benign tumour

·       usually asymptomatic

·       found incidentally either during ultrasonography/CT scanning

·       occasionally, when large, it may cause abdominal pain/shock

o      due to rupture

o      leading to surgical excision

·       appearances with ultrasonography usually diagnostic

o      but, for certainty, may need

§       CT scan with contrast,

§       angiography, or

§       MRI

 

Hepatic adenoma

 

·       incidence of tumour seems to have increased markedly since introduction of oral contraceptive pill

o     most reported cases in females who have been on the pill ³ 5 years

o     however, risk for individual woman is infinitesimal

·       patients often asymptomatic

o      mass discovered on physical examination

o      or incidentally on ultrasound examination

·       some patients complain of upper abdominal pain

·       others present acutely with shock due to intraperitoneal bleeding

·       tumour

o      usually solitary

o      but may be multiple

o      consists of cords/acini of hepatocytes without bile ducts or portal tracts

§       fibrous tissue septa sparse

o      may be encapsulated

o      little or no disturbance in liver function

o      a-foetoprotein concentrations normal

·       ultrasonography shows focal lesion of variable echogenicity

·       CT scanning shows marked arterial enhancement

o      sometimes areas of haemorrhage within tumour

§       can be confirmed on MRI scanning

·       in some cases, tumour has regressed after withdrawal of contraceptive pill

o      surgical resection usually recommended because of risk of intraperitoneal bleeding

o      occasional development of malignant change

 

Focal nodular hyperplasia

·       benign condition

·       uncertain pathogenesis

·       frequently confused with hepatic adenoma

·       lesion composed mainly of

o      hepatocytes

o      Kupffer cells

·       typically

o      central stellate scar,

o      radiating septa containing

§       arterial channels

§       venous channels

§       bile ductules

·       much more frequent in women than men

o      but no relationship to oral contraceptive pill has been established

·       mass usually solitary and asymptomatic

o      but rupture with intraperitoneal bleeding occasionally occurs

·       imaging

o      findings often different from those of hepatic adenoma

o      may allow definitive diagnosis

o      Doppler US – may show an arterial signal within the tumour

o      CT scanning or MRI scanning – may demonstrate central stellate scar

o      biliary scintiscanning may show a late hotspot in the tumour

·       prognosis is excellent

·       malignant change is not recorded

·       but, if imaging techniques do not provide definite diagnosis, surgical excision often recommended

 

Other benign tumours

 

·       much rarer; include

o      fibroma,

o      lipoma,

o      leiomyoma,

o      cystadenoma