Книга_1444_Библиотеки_им_академика_М_И_Перельмана

Добавил:

Sekretar kiopkiopkiop18@yandex.ru t.me/Prokururor I Вовсе не секретарь, но почту проверяю Опубликованный материал нарушает ваши авторские права? Сообщите нам.

Вуз:

Ростовский Государственный Медицинский Университет

Предмет:

Медицина общая

Файл:

Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_1444_Библиотеки_им_академика_М_И_Перельмана.pdf

Скачиваний:

Добавлен:

10.10.2026

Размер:

10 Мб

Скачать

☆

<<< < Предыдущая 12 13 14 15 16 17 18 19 20 21 22 2324 / 4724 25 26 27 28 29 30 31 32 33 34 35 36 > Следующая >>>

Chapter 17 / Benign Liver Tumors 211

percutaneous interventions should be employed as palliative procedures

when surgery is not feasible. Benzimidazoles are always indicated and, in

the setting of surgical resection, given as lifelong adjuvant therapy.

Liver transplantation can be considered in the setting of patients who

have severe liver insuciency secondary to biliary cirrhosis or Budd-Chiari

syndrome, recurrent cholangitis, inability to perform radical liver resection

(i.e., lack of hepatic reserve), and the absence of extrahepatic disease. As of

2003, 45 liver transplantations have been performed for AE with variable

success.

Pyogenic Liver Abscess

Presentation

Pyogenic (bacterial and fungal) liver abscesses (PLA) were once complica-

tions from inadequately treated appendicitis, diverticulitis, or other intra-

abdominal infections. Biliary sources are now the primary causes of PLA.

e incidence is estimated at 20 cases per 100,000 hospital admissions with

the average patient between 50 and 60 years of age and of male predomi-

nance. e incidence of PLA is not associated with ethnicity or geographic

location.

Abscesses can be divided into six categories based upon the route of

infection listed in order of descending frequency: (1) biliary (60%), (2) cryp-

togenic (17%), (3) hepatic artery (10%), (4) portal vein (7%), (5) penetrat-

ing trauma (5%), and (6) direct extension (3%). Iatrogenic causes include

biliary–enteric anastomoses, liver-directed therapies for malignancy, and

transplantation. Escherichia coli and Klebsiella pneumoniae are the most

common pathogens followed by Staphylococcus aureus, Enterococcus spp.,

Streptococcus viridans, and Bacteroides. e incidence of Klebsiella as the

primary pathogen in liver abscesses has increased recently, particularly

in those with diabetes mellitus. PLA have become a unique complica-

tion associated with patients undergoing chemotherapy with hepatotoxic

drugs, such as oxaliplatin (sinusoidal obstruction syndrome) and irinote-

can (steatohepatitis), for treatment of hepatic metastases. Drug-induced

liver injury is postulated to cause increased susceptibility to liver abscess

formation.

Fever, right upper quadrant abdominal pain, nausea, vomiting, mal-

aise, chills, and weight loss are common presenting symptoms. Elevated

transaminases and/or obstructive jaundice can be present on laboratory

evaluation. Leukocytosis is frequently but not always present. Bacteremia

is present 50% to 95% of the time. Severe complications such as intraperi-

toneal or pericardial rupture, empyema, and broncho–pleural–hepatic

stulae are rare.

Diagnosis

e diagnosis of PLA is dependent on imaging studies, where they can be

solitary or multiple. e right hepatic lobe is most often involved, although

a miliary presentation can occur. CT imaging with intravenous contrast is

the preferred modality with a diagnostic accuracy of 93% to 96%. Imaging

reveals a hypodense lesion, uni- or multiloculated, without contrast

enhancement surrounded by rim enhancement with or without the pres-

ence of gas (Fig. 17.3). Cross-sectional imaging can also demonstrate a likely

cause in approximately 70% of cases.

Treatment

Treatment primarily involves parenteral antibiotics and percutaneous

drainage, which has a success rate of 60% to 90%. Antibiotics are usually

Section II / Liver212

continued for 4 to 6 weeks and tailored to culture results. Repeated per-

cutaneous aspiration without drain placement can be considered in those

with solitary, unilocular abscesses 1 to 3cm in diameter. No randomized

controlled trial has compared percutaneous aspiration versus drain place-

ment. Percutaneous drainage carries a 5% to 6% mortality rate.

Surgical drainage is reserved for patients who fail percutaneous drain-

age. In patients with a biliary source of pyogenic liver abscess, failure of

percutaneous drainage is associated with biliary stula. In these patients,

endoscopic biliary decompression should be combined with percutane-

ous drainage to resolve the abscess without requiring surgical interven-

tion. Surgical drainage can be approached laparoscopically or with formal

hepatic resection. No studies have compared the eectiveness of these

approaches.

Amebic Liver Abscess

Presentation

Liver abscess is the most common extraintestinal site of amebic infection

but occurs in less than 1% of Entamoeba histolytica infections. E. histolyt-

ica is endemic to tropical and temperate climates, such as Mexico, India,

Indonesia, sub-Saharan Africa, and Central and South America. It most

commonly aects men between 20 and 40 years of age.

e disease is contracted via ingestion of contaminated water or

food, which typically results in dysentery. However, the trophozoite can

burrow through the colonic mucosa in certain hosts to enter the portal

circulation and form an abscess within the liver. Clinical presentation

usually occurs within 8 to 20 weeks. Signs and symptoms most commonly

include right upper quadrant abdominal pain, high fever (>38.5°C), and

tenderness to liver palpation. Amebic dysentery and liver abscess rarely

occur together.

Laboratory evaluation demonstrates leukocytosis without eosino-

philia, elevated alkaline phosphatase, and occasional transaminitis.

FIGURE 17.3 Axial CT imaging of a pyogenic liver abscess presenting in a 49-year-old male

alcoholic. The abscess presented in the context of an acute bout of alcohol-inducted hepatitis

associated with portal vein thrombosis and was managed by percutaneous drainage and

antibiotic administration.

Chapter 17 / Benign Liver Tumors 213

Diagnosis

Imaging and serology remain the cornerstones of accurate diagnosis.

Enzyme-linked immunoabsorbent assay (ELISA) has a sensitivity of

99% and a specicity of 90% for amebic liver abscess. is test should be

repeated in 7 days if the initial result is negative due to the delayed forma-

tion of antibodies. Furthermore, patients from endemic regions may have

positive serology due to previous infection. Serum antigen detection assays

can also be used to aid in diagnosis.

It is dicult to distinguish between pyogenic and amebic liver abscess

on imaging as they demonstrate similar features (e.g., rim enhancement).

Percutaneous aspiration of an amebic abscess typically yields an odorless,

reddish-brown “anchovy paste” uid composed of necrotic hepatocytes.

Trophozoites are seen in less than 20% of aspirates. Superinfection of ame-

bic abscesses with enteric bacteria may occur.

Treatment

Amebic abscesses are treated with an amebicidal agent and a luminal agent.

Metronidazole for 7 to 10 days and either paromomycin or iodoquinol for

7 days provide adequate treatment. Percutaneous aspiration or surgical

drainage is rarely necessary in amebic liver abscesses except when abscesses

are greater than 6cm. Intracavitary injection of metronidazole during per-

cutaneous aspiration is an eective strategy for larger abscesses (Table 17.2).

BENIGN SOLID LESIONS OF THE LIVER

Hemangioma

Presentation

Cavernous hepatic hemangiomas are the most common solid benign liver

tumor with an overall prevalence of 5% to 20%. Hemangiomas occur pre-

dominantly in females (2–6:1) between 30 and 50 years of age. ey are

thought to arise from congenital hamartomas due to progressive ectasia. No

causal link to estrogen therapy has thus far been identied. Hemangiomas

are most often asymptomatic and are discovered incidentally on abdominal

imaging. Symptoms occur in approximately 12% of patients, usually due to

capsular stretch or compression of adjacent structures. Symptoms include

right upper quadrant pain, palpable midepigastric mass, nausea, early sati-

ety, or dyspepsia. Rarely, patients may present with Kasabach-Merritt syn-

drome, a consumptive coagulopathy manifesting with thombocytopenia,

hypobrinogenemia, and systemic bleeding. Hemangiomas have no malig-

nant potential and rarely if ever rupture.

Diagnosis

Ultrasonography yields a sensitivity of 60% to 70% and specicity of 60%

to 90% for identication. Multiphase CT and MRI are more accurate than

is ultrasound. Peripheral nodular contrast enhancement with centripetal

lling is the classic presentation of hemangioma on multiphase imaging.

Magnetic resonance imaging has reported sensitivity and specicity of 95%

in identifying hemangiomas. Because of this, excellent accuracy angiog-

raphy or biopsy is no longer used to diagnose hemangiomas. Surveillance

imaging is generally not recommended unless there is uncertainty regard-

ing the diagnosis or symptoms develop.

Treatment

Most hemangiomas remain asymptomatic and stable over time. Inter vention

to prevent future complications is not justied. Rare case reports of hem-

angioma rupture associated with large size or trauma are not enough

Section II / Liver214

Risk Factors or

Associations

Potential

Complications

Malignant

Potential

Initial Diagnostic

Modality Initial Therapy Follow-up

Simple Cyst Age > 60 y

Female gender

Portal hypertension, hemorrhage,

biliary obstruction, bacterial

superinfection, rupture

None Ultrasound None unless

symptomatic

None required

regardless of

intervention

Polycystic Liver

Disease

Intracranial aneurysms, mitral

valve prolapse, mitral valve

regurgitation, pancreatic cysts,

renal cysts

Portal hypertension, hemorrhage,

biliary obstruction, bacterial

superinfection, rupture

Rare Ultrasound None unless

symptomatic

None unless

symptoms recur

Cystadenoma Female gender Obstructive jaundice, chronic

cholecystitis, cholelithiasis

Yes Ultrasound/MRI Surgical resection None

Cystic

Echinococcus

Endemic regions Portal hypertension, cholestasis,

Budd-Chiari syndrome,

bacterial superinfection,

rupture, anaphylaxis

None Ultrasound and

serology

Depends on WHO

classication

Depends on WHO

classication

Alveolar

Echinococcus

Endemic regions Cholestasis None Ultrasound and

serology

Depends on WHO

classication

Depends on WHO

classication

Pyogenic Liver

Abscess

Iatrogenic (biliary-enteric

anastomosis, liver direct

therapies, transplantation)

Rupture, empyema, broncho–

pleural–hepatic stula, septic

shock

None Multiphase CT Antibiotics ±

percutaneous

drainage

None unless

symptoms recur

Amebic Liver

Abscess

Endemic regions,

immunocompromise, history of

splenectomy

Rupture, empyema, broncho–

pleural–hepatic stula, septic

shock

None Ultrasound and

ELISA

Pharmacologic None unless

symptoms recur

Management of Benign Cystic Liver Lesions

TABLE

17.2

Chapter 17 / Benign Liver Tumors 215

to warrant prophylactic surgery. Surgical resection can be considered in

patients with symptoms, in lesions in which malignancy cannot be excluded,

or to treat complications. Enucleation is the operation of choice due to a sig-

nicantly lower rate of perioperative morbidity compared to hepatic lobec-

tomy. Radiofrequency ablation (RFA) and cryotherapy have also been used

in select situations.

Focal Nodular Hyperplasia

Presentation

Focal nodular hyperplasia (FNH) is the second most common benign solid

hepatic lesion after hemangiomas. e reported incidence of FNH is 0.3% to

3%, though only 0.03% have clinical signicance. ey are associated with

female gender (8:1) and occur between 30 and 50 years of age. Concurrent

adenomas are diagnosed in up to 3.6% of patients and concurrent heman-

giomas in up to 23% of patients with FNH. FNH is not associated with OCPs

or pregnancy. Lesions are typically found incidentally, and symptoms are

associated with capsular stretch or compression of adjacent structures. No

malignant potential and no potential to rupture spontaneously have been

associated with FNH.

Diagnosis

e classic description of FNH is a lobular mass with homogeneous arte-

rial enhancement, radiating brous septa, and a central, nonenhancing scar.

is pattern is detected, however, in only 40% to 50% of cases. e diagnosis

of FNH must be dierentiated from that of hepatocellular adenoma as these

two entities are managed dierently. Multiphase MRI with liver-specic con-

trast agents has been shown to have a sensitivity and specicity of 97% and

100%, respectively, in dierentiating FNH from adenoma. In addition, FNH

should also be distinguished from brolamellar hepatocellular carcinoma

(HCC), which also demonstrates a central scar. Characteristics of brola-

mellar HCC include large size greater than 10cm, heterogeneous enhance-

ment, presence of calcications, and hypointensity of the central scar on

T2-weighted MRI imaging compared to the hyperintensity seen with FNH.

Treatment

Symptoms or the inability to exclude malignancy are the indications for

intervention. Hepatic enucleation or lobectomy remains the procedure of

choice, although interventional procedures involving embolization and

RFA have also been used.

Hepatocellular Adenoma

Presentation

HCA is a benign neoplasm composed of hepatocyte proliferation. ese

lesions occur in the population with a female:male ratio of 11:1, and usu-

ally present between 30 and 40 years of life. Risk factors for HCA develop-

ment include OCP use and pregnancy in females and anabolic steroid use in

males. A subset of patients with glycogen storage diseases type Ia and type III

can develop HCA, typically with a male:female 2:1 predominance. Patients

with HCA present with pain 25% to 50% of the time or are otherwise asymp-

tomatic with the lesion incidentally discovered on axial imaging. ey are

isolated lesions located commonly within the right hepatic lobe. Liver

adenomatosis occurs when more than 10 lesions are present (see below).

Lesions greater than 5 cm, OCP use, and pregnancy are risk factors for

rupture or hemorrhage with the classic presentation of sudden-onset right

upper quadrant pain followed by hypotension. Rupture and hemorrhage are

Section II / Liver216

relatively rare events. HCAs carry a potential for malignant transformation

in up to 11% of lesions. Adenomas occurring in men, lesions greater than

5cm, those associated with androgen steroid use, and those associated with

beta-catenin gene mutations are more likely to be malignant.

HCAs are classied into three histopathologic varieties: (1) Steatotic

HCA caused by hepatocyte nuclear factor 1a (HNF1α) mutation, (2) inam-

matory HCA caused by IL-6 signal transducer (IL6ST) mutation, or (3)

HCAs associated with β-catenin mutation. Inammatory HCA is the most

common variant representing 35% to 50% of HCAs. e specic subgroup

of HCA involving β-catenin mutations may have a greater risk for malig-

nant transformation compared to those with HNF1α or IL6ST mutations.

Further investigation is needed to determine the benet of histopathologic

diagnosis. Core needle biopsy itself carries a risk of sampling error, bleed-

ing, and the theoretical risk of biopsy tract seeding.

Diagnosis

e conrmatory diagnosis of HCA is challenging because of its heteroge-

neous imaging features, particularly in the setting of necrosis, old or recent

hemorrhage, and calcic foci. Ultrasound has no utility in diagnosis of

HCAs unless contrast enhancement is used. Contrast enhanced ultrasound

reveals a centripetal enhancement during arterial phase compared to a cen-

trifugal lling pattern in FNH. Multiphase CT scan is more useful than ultra-

sound to diagnose HCA, but its utility lies in its ability to identify FNH and

hemangiomas to rule out HCA. Multiphase MRI with liver-specic contrast

agents provides the best denitive diagnosis and can be used to suggest the

subtype. Steatotic adenomas display diuse signal dropout on T1-weighted

chemical shift sequence associated with their high fat density, and are mod-

erately enhancing in the arterial phase without persistent enhancement in

the portal venous and delayed phases. is pattern yields a sensitivity and

specicity of 86% and 100%, respectively. Inammatory adenomas display

high-intensity signal on T2-weighted MRI and lack of signal dropout of fat

suppression images and have strong arterial enhancement with persistent

enhancement of portal venous and delayed phases. is pattern yields a

sensitivity and specicity of 85% and 87%, respectively. Unfortunately, no

particular MRI pattern has been associated with β-catenin mutated lesions,

which carry the greatest potential for malignant transformation.

Treatment

Patients who take OCPs or anabolic steroids should be advised to discontinue

these medications as this may lead to regression of the lesion. Treatment

modalities include RFA, transarterial embolization (TAE), and hepatic

resection. Hepatic resection, either anatomic segmentectomy/lobectomy

or enucleation, is preferred. To date, no clinical trial has compared RFA or

TAE against surgical resection. Surgical resection is indicated in all adeno-

mas occurring in men, those that cause symptoms or hemorrhage, and those

greater than 5cm in women. Adenomas that have ruptured should be man-

aged initially with resuscitation followed immediately by TAE. Resection

during acute rupture has a reported mortality of 8% to 10%. In addition to

hemorrhage control, TAE has been shown to cause tumor shrinkage. Lesions

that are smaller than 5cm in size should be surveyed for growth. A typi-

cal regimen includes ultrasound examination every 3 months for 6 months

and extending the duration thereafter if no growth or suspicious features

are detected. Patients who develop symptoms should be oered resection.

Women with adenomas greater than 5 cm in size are advised to

undergo resection prior to conception. Women who are diagnosed with

adenomas during pregnancy are advised to undergo elective resection

Chapter 17 / Benign Liver Tumors 217

during the second trimester for lesions greater than 5cm in size. Lesions

that are discovered in the third trimester should be monitored with serial

ultrasound exams as the rare risk of spontaneous rupture exists (Fig. 17.4).

Hepatic Adenomatosis

Presentation

Liver adenomatosis refers to the patient with arbitrarily dened greater

than 10 HCAs. e presentation is identical to that of isolated HCAs. It has

been argued that adenomatosis is not a separate entity from solitary HCAs.

Diagnosis

Histologic and radiographic features of adenomatosis are identical to that

of isolated HCA.

Treatment

e optimal mode of treatment has not been dened due to the rarity of

presentation and the diculty of isolated lobectomy. Treatment options

include a combination of surgical resection, RFA, and TAE. Orthotopic liver

transplantation has been performed in rare cases. e number of adeno-

mas is not associated with increased risk of malignant transformation or

hemorrhage. Treatment should be aimed at the lesion greater than 5cm in

size with close surveillance of the remaining lesions.

Nodular Regenerative Hyperplasia

Presentation

Nodular regenerative hyperplasia (NRH) occurs when normal hepatic

parenchyma is transformed into 1- to 3-mm regenerative nodules sepa-

rated by atrophic areas without the presence of perisinusoidal brosis as

seen in cirrhosis. is condition is thought to occur due to altered blood

FIGURE 17.4 Axial CT imaging demonstrating a large hepatic adenoma in a 55-year-old

woman presenting with hypotension and anemia. The scan demonstrates evidence of hem-

orrhage into the tumor. This patient was managed with selective embolization to the right

hepatic lobe mass and interval right hepatic lobectomy.

Section II / Liver218

ow causing hepatocyte hyperplasia in regions with adequate blood ow

and atrophy in regions with ischemia. NRH is a rare condition with autopsy

studies demonstrating an overall incidence between 0.7% and 2.6%. Our

understanding of the condition is limited to case reports with only approxi-

mately 350 cases reported from 1975 to 2011. It most commonly presents

in middle age and increases in frequency with age. ere is no association

with gender or ethnicity. It is felt that NRH occurs in response to other sys-

temic perturbation including immunologic, hematologic, medication-asso-

ciated, cardiac, or pulmonary conditions.

Patients with NRH are usually asymptomatic and detected on workup

of the underlying systemic condition. When symptoms do occur, they are

the result of portal hypertension. Dierentiation should be made between

NRH and large regenerative nodules (LRN), which occur in the presence of

hepatic outow obstruction, such as in Budd-Chiari syndrome.

Diagnosis

Suspicion for NRH usually occurs during the evaluation of portal hyperten-

sion especially in the patient without evidence of cirrhosis. Imaging studies

in the diagnosis of NRH cannot readily distinguish LRN from the regenera-

tive nodules of cirrhosis. Imaging subsequently is most useful for the exclu-

sion of other hepatic lesions. Denitive diagnosis depends on liver biopsy

with histopathologic analysis.

Treatment

Treatment of NRH is geared towards management of the underlying condi-

tion and the management of portal hypertension when it occurs. Standard

therapies for portal hypertension should be employed, including dietary

changes, medical management of ascites, endoscopic intervention for vari-

ces, and surgical shunting procedures or transjugular intrahepatic porto-

systemic shunts (TIPS). Orthotopic liver transplantation can be considered

in the patient with hepatic failure. Mortality from NRH is most commonly

due to variceal bleeding.

Angiomyolipoma

Presentation

Angiomyolipomas (AML) are rare, benign mesenchymal tumors most often

found in the kidney. Only approximately 300 cases of hepatic AML have been

reported between 1976 and 2012. ese lesions are well-circumscribed, soft

masses composed of mature fat cells, blood vessels and smooth muscle.

eir pathogenesis is unknown, and lesions are usually incidentally iden-

tied on diagnostic imaging. Both renal and hepatic AML are associated

with tuberous sclerosis complex. Patients reporting symptoms usually have

large AML causing capsular stretch or compression of adjacent structures.

Spontaneous rupture has been reported rarely.

Diagnosis

e accurate diagnosis of AML depends upon the proportion of fat, smooth

muscle, and blood vessels within the lesion. Generally, lesions that contain

predominantly fat are more accurately diagnosed with imaging and those

lesions containing less fat are commonly mistaken for malignancy (e.g.,

HCC, metastasis, liposarcoma). In general MRI with hepatic-specic con-

trast agents remain the best imaging modality for diagnosis, though the

overall accuracy of MRI is still poor. In a recent series of 79 patients under-

going surgical resection for presumed AML, 48% were diagnosed incor-

rectly preoperatively with imaging or angiography.

Chapter 17 / Benign Liver Tumors 219

Risk Factors or

Associations

Potential

Complications

Malignant

Potential

Initial Diagnostic

Modality Initial Therapy Follow-up

Hemangioma Female gender Kasabach-Merritt

syndrome,

rupture

None Multiphase CT None unless

symptomatic

None unless

symptomatic

Focal Nodular

Hyperplasia

Female gender None None Multiphase MRI None unless symptomatic

or cannot exclude

malignancy

None unless

symptoms recur

Hepatocellular

Adenoma

Female gender, OCPs,

pregnancy, glycogen

storage disorders,

anabolic steroids

Rupture,

hemorrhage

Yes Multiphase MRI Surgical resection if

> 5cm

Surveillance for

growth

Hepatic

Adenomatosis

Same as hepatocellular adenoma

Nodular Regenerative

Hyperplasia

Secondary to other

systemic conditions

Portal hypertension None Tissue biopsy Management of

underlying condition

None unless

symptomatic

Angiomyolipoma Tuberous sclerosis Rupture rarely Rarely Multiphase MRI Surgical resection if

> 6cm or cannot

exclude malignancy

Surveillance for

growth

Management of Benign Solid Liver Lesions

TABLE

17.3

Section II / Liver220

Treatment

e preferred treatment of AML is controversial due to the rarity of

the condition. In general, AML has been treated as a benign liver lesion;

however, case reports of malignant transformation presenting as vascu-

lar invasion or metastatic disease have been published. Because of these

observations, surgical resection is recommended in lesions greater than

6cm, lesions that demonstrate rapid growth during surveillance, or lesions

in which malignancy cannot be denitively excluded. Patients who have

undergone percutaneous biopsy should be considered for surgical resec-

tion if vascular invasion, atypical epithelioid component, or p53 immunore-

activity is found on histopathologic examination (Table 17.3).