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“The only thing necessary for these diseases to the triumph is for good people and governments to do nothing.”

      

Atlas of Liver Pathology:Vascular Alterations in the Liver

Diseases Affecting the Vasculature of the Liver

 

For Providers

Atlas of Liver Pathology: Chapter 3, Vascular Alterations in the Liver

Diseases Affecting the Vasculature of the Liver

Frank A. Mitros, M.D.
Peer Review Status: Internally Peer Reviewed

The vasculature of the liver is frequently affected in systemic processes. Thromboses of the major vessels may affect either outflow (hepatic vein) or inflow (portal vein, hepatic artery). The exact location and mechanism of thrombosis will lead to vastly different outcomes. The most important of these diseases is the group which results in hepatic venous outflow obstruction.

In addition, the hepatic vessels can be affected directly by such systemic diseases as vasculitis, or indirectly as a result of an adverse effect of drugs or the remote effects of neoplasia.

Hepatic Venous Outflow Obstruction

There are a number of clinical situations in which the outflow of blood from the liver is impeded by an obstructive process which may be thrombotic or nonthrombotic, and affect either extrahepatic or intrahepatic vessels or both. The two classic clinical syndromes defining the ends of this spectrum are Budd-Chiari syndrome and veno-occlusive disease, but many areas of overlap or variations on this theme exist.

Budd-Chiari Syndrome

In the most classic form of the syndrome patients present with striking hepatomegaly, abdominal pain and ascites. There may also be mild jaundice. This follows the development of obstruction of either the larger branches of the hepatic vein as they leave the liver or of the vena cava into which they empty before it enters the right atrium.. Thus patients with severe right sided failure, such as might be seen in tricuspid insufficiency, are not considered to have Budd-Chiari syndrome, although their clinical appearance may be identical to that just described. Patients with chronic obstructive lesions may have developed sufficient collateral circulation so that ascites may not be present.

In a large portion of the world, including South Africa, Japan and India, the most common underlying lesion is a membranous obstruction in the inferior vena cava. The nature of the fibrous web within the cava is very poorly understood. It may represent organization of a prior thrombus. In the United States, such webs are not commonly seen and more obvious thrombotic events are the usual underlying event. There are a number of reasons for thrombosis to occur. The more commonly reported clinical situations include hematologic diseases (particularly polycythemia rubra vera, paroxysmal nocturnal hemoglobinurea, and myelofibrosis), trauma, infection (ameba, hydatid disease), and coagulopathies (protein C deficiency). Another cause encountered with some frequency is tumor invasion of the hepatic vein, particularly hepatocellular or renal cell carcinoma In about 25% of cases no cause can be identified. Of paramount importance, severe cardiac failure must be excluded, since the gross and microscopic appearance of severe failure may be indistinguishable from that of Budd-Chiari syndrome.

Grossly the liver is enlarged and congested . With thrombosis of large intrahepatic veins Zahn's infarcts may develop. The distribution within the liver may be quite irregular ; the caudate lobe is particularly likely to be spared since it has some venous branches that empty directly into the cava.

The changes histologically are those seen with acute congestion, and are almost purely those of severe right sided failure. Significant coagulative necrosis is not regularly seen, although the massive congestion may lead to significant loss of zone 3 hepatocytes. While one cannot make a definitive diagnosis of Budd-Chiari syndrome from the histology alone, several features do favor the diagnosis. The centrilobular congestion is particularly severe and uniform in the affected areas of liver There may be significant loss of centrilobular hepatocytes Although the terminal hepatic venules are usually patent, organizing thrombi may be seen on occasion in the large sublobular veins Significant extravasation of blood into the space of Disse and the hepatocyte cords is very common . If the underlying cause is not corrected, fibrosis occurs and the picture of cardiac sclerosis appears.

Veno-occlusive Disease (VOD)

The other major cause of hepatic venous outflow obstruction is veno-occlusive disease; it differs from Budd-Chiari syndrome in that it is the smaller intrahepatic venules within the liver that are primarily involved usually in a non-thrombotic manner. There is usually a defined exposure to a toxic agent or physical injury. In some parts of the world naturally occurring toxins (pyrrolizidine alkaloids - Jamaican bush tea) remains a significant cause of hepatic disease, particularly in children. Presently in the United States bone marrow transplantation is the most frequent setting for the development of VOD. This is related to the radiation and chemotherapeutic agents used in these patients. Renal transplant patients receiving immunosuppression agents are also at risk for VOD.

The clinical presentation resembles that of Budd-Chiari syndrome with the sudden onset of ascites and hepatomegaly, although the clinical background is usually quite different. While it was originally thought to be a complication limited to the early period after bone marrow transplantation (the first month) it is clear that VOD can appear many months after the transplant.

The histology of VOD is again that seen in severe right sided failure. It differs from both Budd-Chiari syndrome and failure by the fact that it is characteristically erratically distributed throughout the liver . More importantly, the terminal hepatic venules show a characteristic histologic lesion. Not all venules are involved, and the erratic distribution of the involved vessels matches that of the areas of congestive type change. While the histology of the venous lesion is characteristic, it can be easily overlooked. Trichrome or reticulin stains are a must in these circumstances. There is a narrowing of the lumen, with eventual complete obliteration of the lumen. In the earliest stages the intima appears to be strikingly edematous with red blood cells trapped amongst wisps of loose connective tissue . As the lesion progresses, the edema is replaced by more dense fibrous tissue and macrophages with hemosiderin may be present . Eventually the lumen can become completely obliterated , and the individual lesion cannot be distinguished from chronic Budd-Chiari syndrome or from cardiac sclerosis.

    

Extrahepatic Portal Vein Obstruction

Obstruction of the portal vein outside the liver does not usually cause significant parenchymal damage, but may mimic or complicate hepatic disease. The obstruction is likely thrombotic in origin in the majority of cases, although the thrombus may not be recognizable as such at the time of diagnosis. The usual finding is an area of obliteration in the portal vein surrounded by a large number of collateral vessels. The liver is usually histologically normal. The portal vein may be involved alone, or in combination with the splenic or splenic and mesenteric veins. Patients present with clinical features of portal hypertension. Ascites may be present early on, but often resolves. Hematemesis from varices is the most common problem, but portal encephalopathy or features of hypersplenism may also occur.

Extraheptic portal venous obstruction is seen most commonly in children, where it was once believed to be a complication of umbilical sepsis. This view has been questioned since a history of omphalitis and intra-abdominal sepsis has been documented in relatively few patients, and there is a seemingly higher than expected incidence of a variety of congenital abnormalities. The process can also be seen in adults, where it may complicate sepsis or pylephlebitis. Infection remains the overall most commonly identified precipitating factor at all ages. Abdominal trauma or surgical injury are documented causes of such obstruction, as is invasion of the portal venous system in neoplastic processes. The thrombotic and gynecologic disorders associated with Budd-Chiari syndrome have also been seen in the setting of portal venous obstruction, although the portal venous system is much less frequently involved than the hepatic venous system. Pancreatitis can give rise to splenic vein thrombosis, which can then propagate and involve the portal vein; this may present a particularly difficult diagnostic dilemma in patients who are alcoholics. A very high percentage of cases remain idiopathic; of interest is the fact that a large number of such cases are seen in parts of the world such as India where idiopathic portal hypertension is frequent (see below). The main clinical problem is to clearly distinguish patients with this condition from those whose portal hypertension is related to parenchymal liver disease. Unfortunately, cirrhosis of many etiologies may itself be complicated by a secondary extrahepatic portal vein thrombosis. The relationship amongst these diseases affecting the hepatic vessels is depicted diagrammatically 

Sinusoidal Dilatation

Most commonly significant dilatation of the sinusoids is due to hemodynamic failure or to venous outflow obstruction. There are a number of situations where the sinusoids themselves appear to be affected.

Peliosis hepatis is characterized by blood filled spaces in the liver which are almost always multiple The size range is from several millimeters to several centimeters in diameter; in the latter instance they may cause confusion with vascular tumors (see Chapter 11). Although peliosis may be associated with hepatomegaly and even hepatic failure, it is more commonly a lesion found incidentally. Two types have been described. In one, the parenchymal variant, there are cystic spaces filled with blood and without an endothelial lining . In the other, the phlebectatic variant, the prominent vascular spaces are in continuity with what appears to be dilated sinusoids . The types may coexist; both may result in thrombosis. Presumably the precipitating condition weakens or damages the sinusoidal lining in some fashion. Tuberculosis was formerly the most common underlying disease, but it is now seen most frequently as a complication of the use of androgenic-anabolic steroids. It has also been seen complicating a variety of tumors, and occasionally in hypervitaminosis A or complicating hemodialysis for renal failure. Peliosis-like changes can be seen in hepatic adenomas (see Chapter 11).

Hodgkin's disease frequently shows a peculiar unexplained sinusoidal dilatation, and may even show overt peliosis. The reasons for this phenomenon are not understood.

Pregnant patients or patients on oral contraceptives may show a peculiar sinusoidal dilatation showing selective involvement of zone 2 .

Miscellaneous causes of sinusoidal dilatation also include AIDS, chenodeoxycholic acid therapy for gallstones, and the presence of nearby space occupying lesions.

Systemic Vascular Disease

The liver is affected in a variety of systemic diseases involving the vessels; usually the manifestation in other organs are more important than those in the liver.

Vasculitis involves the liver not infrequently. Known causes include polyarteritis nodosa, systemic lupus erythematosis, rheumatoid arthritis, and temporal (giant cell) arteritis. The intrahepatic vessels may show fibrinoid necrosis , and aneurysms and hemorrhage may be found. Polyarteritis is of particular interest because it may be related to hepatitis B infection. The liver in such patients typically show an active vasculitis in the setting of a liver showing minimal histologic evidence of damage by the chronic hepatitis .

Atherosclerotic cardiovascular disease may affect the intrahepatic vessels. Cholesterol emboli may be seen in patients will severe atherosclerosis . Such lesions are usually of no clinical significance. Systemic hypertension may cause hyaline arteriosclerosis in portal triad vessels. Likewise the vascular changes of diabetes mellitus may be identified in vessels within the triads.

Patients with hairy cell leukemia may have cystic spaces lined by the leukemic cells in the portal areas or in the lobules. These spaces are filled with red blood cells and may be mistaken for peliosis.

Patients with Osler-Weber-Rendu Disease (hemorrhagic hereditary telangiectasia) may have large thin walled portal vessels that may extend into the parenchyma and become associated with fibrosis . The resulting appearance has been referred to as pseudo-cirrhosis; nodular regenerative hyperplasia may occur.

Patients with sickle cell anemia may have a variety of liver problems. In crisis there may be sequestration of large numbers of sickled red blood cells in the sinuses with subsequent mild hepatocyte necrosis. More typical liver diseases, such as obstructive processes from complicating gallstones, or intercurrent viral hepatitis are more common and must be excluded before attributing the liver dysfunction to the vascular phenomenon.

Disseminated intravascular coagulation may manifest in the liver with sinusoidal microthrombi which may extend into central veins on occasion.

Idiopathic Portal Hypertension

When such causes of portal hypertension as cirrhosis, extrahepatic portal vein obstruction, and infections such as Schistosomiasis have been excluded there remains an enigmatic group of patients who present with clear-cut evidence of portal hypertension of uncertain etiology. Most of these patients would fit under the previously used rubric of Banti's syndrome. As our understanding of the clinical and pathologic aspects of this process have progressed, a number of synonyms have appeared in the world's literature. These include idiopathic portal hypertension (IPH), noncirrhotic portal hypertension or fibrosis (NCPF), and hepatoportal sclerosis.

There is a striking geographic variability in incidence. There are also some relatively subtle differences in the way the disease manifests itself in different parts of the world. In Japan, where it is usually known as IPH, the patients are typically middle aged women; 75% of patients are female, and the mean age of presentation is 36, although patients in their 50's are not uncommon. In these patients gastrointestinal bleeding, splenomegaly, or anemia are equally frequent modes of presentation. In India, where the process is usually referred to as NCPF, the usual patient is a young man; 80% of the patients are male, and the mean age of presentation is 30 years of age. Presentation with gastrointestinal bleeding is the rule in the vast majority and anemia or symptomatic splenomegaly are uncommon. Careful physical exam will show splenomegaly in both groups, and hepatomegaly is present about half the time. Not infrequently the liver is smaller than normal. In the United States, the sex incidence is nearly equal and the patients are slightly older, with gastrointestinal bleeding being the usual presentation. Liver function tests are normal or near normal; anemia and leukopenia are frequent.

Parallel similarities and differences exist with regards to the pathology of the these two groups of patients. The liver may look nodular from the surface, but the nodularity is usually relatively superficial; the nodularity is more pronounced in the cases from India. Cirrhosis by definition is not present; the nodules are similar in appearance and pathogenesis to those seen in nodular regenerative hyperplasia or partial nodular transformation. In fact, many believe that the latter term has been incorrectly used to describe patients who actually have IPH or NCRF. There is usually significant fibrosis along the portal vein and its branches particularly near the hilus . Portal vein thrombosis can occur, but this is thought to be a complication rather than a cause of IPH since it usually occurs later in the course of well-established disease.

Microscopically there is no evidence of cirrhosis, although a number of histological clues may be present. The portal vein itself will usually have a thick sclerotic wall rich in elastic fibers . There may be stellate or concentric fibrosis in the portal areas in the advanced cases; the connective tissue in these areas may have a peculiar wrinkled appearance and stain strongly for elastic fibers . There may be diminution or obliteration of portal vein branches within the triads. Frequently abnormal large dilated veins may be seen juxtaposed to the portal triads; these have been mistaken on occasion for terminal hepatic venules . Inflammation and necrosis are not prominent features.

The etiology of this condition is not known. Exposure to such environmental toxins such as arsenic has been suspected but not clearly proven. Infection has also been suspected, perhaps associated with a peculiar immunologic response to subclinical infection. It is of interest that the incidence of NCPF is high in countries like India, where the incidence of extrahepatic portal vein obstruction (more closely linked to episodes of infection) is also high.

Patients with non-cirrhotic portal hypertension have excellent parenchymal reserve. They tolerate the condition well, having much better survival than patients with similar degrees of portal hypertension caused by cirrhosis.

 

All contents copyright © 1992-2003 the Author(s) and The University of Iowa. All rights reserved.

 

Atlas of Liver Pathology: Chapter 3, Vascular Alterations in the Liver

Effects of Systemic Vascular Problems on the Liver


For Providers

Atlas of Liver Pathology: Chapter 3, Vascular Alterations in the Liver

Effects of Systemic Vascular Problems on the Liver

Frank A. Mitros, M.D.
Peer Review Status: Internally Peer Reviewed

There is a striking effect on the liver in situations where significant cardiac dysfunction occurs. These effects will vary greatly depending on how acutely the hemodynamic changes occur and whether or not they are predominantly affecting the right or left side of the circulation (Figure 3-1). In most instances there will be a combination of events affecting the entire circulation occurring over a variable period of time, perhaps modified by pre-existing conditions in the host liver. For purposes of clarity, classic examples of nearly "pure" conditions will be considered separately, although one must be cognizant that these circumstances are much less common than combined lesions.

Acute Right Heart Failure

The cardinal hepatic manifestations of significant right sided heart failure are sinusoidal dilatation and congestion with subsequent atrophy of hepatocyte cords . These changes are clearly zonal, with the centrilobular area (zone 3) being most severely affected; with time and increasing severity there may also be involvement of zone 2 and finally of zone 1. This condition has been referred to as chronic passive congestion and is closely related to elevated pressures in the right atrium or with other conditions leading to an increase in systemic venous pressure. The space of Disse may become more prominent and may contain red blood cells in the more severe lesions. The appearance of the sinusoids can be dramatically altered due to the process of biopsy, particularly with needle biopsies. Blood may drain out of the specimen collapsing the sinusoids, but attention to detail such as atrophic cords and the widened space of Disse provide helpful clues. There is minimal if any necrosis, correlating with the observation that such patients may have normal transaminases or, less commonly, minor elevations (less than 2-fold).

Acute Left Heart Failure

Significant failure of the left side of the circulation is characterized by necrosis of hepatocytes in the centrilobular area . This necrosis is coagulative rather than lytic. It may appear to be asymmetric in zone 3, owing to the variability of blood flow through the various acini It is clear that the presence of centrilobular necrosis correlates closely with the severity of hypotension, whether sustained or episodic. Overt clinical shock need not be present for severe necrosis to develop. When such necrosis is present, there may be dramatic increases in serum transaminases, sometimes leading to a mistaken clinical impression of a viral hepatitis ; this has been referred to by some as ischemic hepatitis. In most cases with significant necrosis there will also be seen evidence of co-existing right sided failure with prominent congestive changes. As necrosis progresses, there may be replacement of hepatocytes within the cords by red blood cells. Associated with this zone 3 necrosis the adjoining intact hepatocytes have been known to contain PAS positive spherical inclusions. While these resemble alpha-1-antitrypsin deficiency inclusions they differ in their location (zone 3 rather than zone 1); they represent damaged enlarged lysosomes.

Chronic Passive Congestion (Cardiac Sclerosis)

Active deposition of perisinusoidal collagen has been noted with right sided failure, and both passive collapse of the reticulin framework as well as active deposition of stromal connective tissue are seen in left sided failure. With long-standing circulatory failure some degree of fibrosis will develop. This is most pronounced in zone 3. This phenomenon of centrilobular fibrosis with sparing of periportal hepatocytes leads to an appearance referred to as "reverse lobulation" The central congestion and fibrosis with pale periportal areas (and perhaps some degree of fatty change in the zone 2 hepatocytes) combine to give an appearance which has commonly been referred to as "nutmeg liver" . If the scarring is allowed to progress, the centrilobular collagen will eventually link with the portal connective tissue. At this stage the condition has been referred to as cardiac cirrhosis , but the term cardiac sclerosis is more accurate in that overall architectural integrity is maintained (see Chapter 9). Even at such a late stage clinical manifestations are usually minor with regards to signs of liver disease, there being minor elevations of serum bilirubin and even less impressive elevations of alkaline phosphatase and transaminases. The clinical picture is dominated by the signs of the underlying cardiovascular disease. In fact, with modern pharmacologic agents, valve replacement technology, and availability of cardiac transplantation, it is quite unusual to see significant hepatic sclerosis based on purely cardiovascular problems.

    

Shock Liver

The liver can be significantly damaged in shock from a variety of causes. With severe hemorrhage, burns, etc. the type of centrilobular necrosis described in left sided failure is seen. Such lesions are uncommon if shock is transitory (less than 10 hours) but are almost invariable if shock persists for 24 hours or more. Similar centrilobular necrosis occurs with severe hyperpyrexia or with heat stroke; in such circumstances the hepatocytes may contain small vacuoles. With septic shock, there may be striking cholestasis and even a prominent cholangitis (see Chapter 8).

Hepatic Infarction

Because of the dual blood supply of the liver (hepatic artery and portal vein) true infarction of the liver has been considered to be rare. This may not be true; there is considerable variation in the incidence of infarction as reported in several autopsy series. In at least one careful series, hepatic infarction, as defined by coagulation necrosis occupying more than one hepatic lobule, was seen in 14 of 700 autopsies. Most other investigators encounter hepatic infarction much less frequently. The underlying defect is usually hepatic arterial occlusion (usually thrombotic). Portal vein occlusion, or combined hepatic and portal vein occlusion, are occasionally found. Even less commonly, no vascular occlusion is identified. Recent abdominal surgery, particularly cholecystectomy, is frequently present historically in patients with arterial or combined arterial and venous thrombosis. Pure venous thrombosis is commonly related to tumor emboli. Patients without demonstrable vascular occlusion frequently have significant cardiovascular disease and have had significant recent hypotensive episodes. Arteritis has been the underlying mechanism in some cases. Recently a number of reports have documented hepatic infarction in liver transplant recipients secondary to the arteriopathy of chronic rejection (see Chapter 12).

Most hepatic infarcts are discovered incidentally at the time of autopsy. Clinical and laboratory findings are poorly defined, probably because they are masked by the overwhelming manifestations of the underlying disease. Sharp elevations of transaminases and mild hyperbilirubinemia and a mild increase in the alkaline phosphatase have been attributed to sublethal infarcts.

Grossly the infarcts are sharply demarcated and a uniform dark red; there is a mottled peripheral zone of congestion . With time the central area becomes pale. The size ranges from 1 to 15 cm in greatest diameter. Typical coagulative necrosis affects the parenchyma, but mesenchymal elements such as triads and central veins appear relatively viable

True hepatic infarction must be distinguished from the atrophic red "infarct' of Zahn. These are areas of severe acute passive congestion with minimal parenchymal necrosis and atrophy (zone 3) resulting from focal thrombotic obstruction of portal vein branches. They present as sharply delimited areas of hyperemia grossly

Pylephlebitis

Suppurative thrombophlebitis involving the portal vein and its intrahepatic branches was formerly much more common. It was most commonly seen complicating delayed treatment of appendicitis in the pre-antibiotic era. Multiple hepatic abscesses resulting from this seeding of the liver was frequently lethal . Abdominal sepsis still remains the most likely underlying mechanism for pylephlebitis, but the spectrum of disease has shifted. Clinically silent diverticulitis is the most common mechanism; complicated inflammatory bowel disease can also lead to pylephlebitis. The involved portal triad may have its architecture obscured by the suppurative process, but earlier lesions will show clear evidence of a fibrin neutrophil coagulum in the intrahepatic branches of the portal vein

 

 


For Providers

Case-Based Learning in Gastroenterology and Hepatology: Hepatic Disorders

Hepatic Hydrothorax

Klaus Bielefeldt, M.D., Ph.D.
Piush Gupta, M.D.

Peer Review Status: Internally Peer Reviewed
Creation Date: October 2000
Last Revision Date: February 2001

63 year-old Caucasian female with biopsy-proven cirrhosis secondary to alpha-1-antitrypsin deficiency complained of shortness of breath and cough productive of scant amounts of mucoid phlegm for 1 week. She denied fevers or chills. In the post, she had undergone a total abdominal hysterectomy and radiation therapy for uterine cancer as well as a sigmoid resection for radiation colitis. Follow up evaluations had not shown signs of cancer recurrence. She did not smoke or drink alcoholic beverages. On physical examination, she appeared in moderate respiratory distress. The right hemithorax was dull to percussion and the vocal fremitus was markedly diminished. Shifting dullness was present on abdominal exam. She had 2+ pitting edema up to her shins bilaterally.

A chest X-ray revealed a large right pleural effusion. The combination of ascites and right-sided pleural effusion in a patient with cirrhosis raised the possibility of a hepatic hydrothorax. A TC99 study demonstrated accumulation of tracer in right hemi-thorax after injection into peritoneal cavity.

The patient was placed on salt and fluid restriction and received diuretics, resulting in dramatic improvement of her symptoms. Serial chest X-rays showed a progressively decreasing size of the pleural effusion. Two weeks after discharge the hepatic hydrothorax had completely resolved .

Discussion:

Hepatic-hydrothorax occurs in 1-5% of cirrhotic patients. Most cases affect the right side. These effusions are usually due to the passage of ascitic fluid into the pleural space through minute defects in the diaphragm. Hepatic-hydrothorax has been reported even in the absence of clinical ascites.

Treatment is primarily medical with salt and fluid restriction, diuretics and if necessary drainage of ascites. Intractable cases may require a more aggressive approach. Transjugular intrahepatic portosystemic shunts (TIPS) is a viable option in selected patients. Chemical pleurodesis by thoracoscopy carries a failure rate in excess of 33%. Thoracotomy to repair the diaphragmatic defects has been tried with very limited success. Chest tube insertion is not indicated, as it does not address the underlying abnormality.

References:

1.    Mouroux J, Perrin C, Richelme H. Management of pleural effusion of cirrhotic origin. Chest. Vol 109. No. 4. April 1996

2.    Johnson D, FD Gordon, Gitlin N. TIPS for patients with refractory hydrothorax: what is the take home message? Am. J. of Gastroenterology Vol 92. No. 11. November 1997

3.    Runyon BA, Greenblatt M, Ring MHC. Hepatic hydrothorax is a relative contraindication to chest tube insertion. Am J Gastroenterology 1986; 81:566-7

 


For Providers

Case-Based Learning in Gastroenterology and Hepatology: Hepatic Disorders

Hepatic Abscess from Streptococcis Milleri

Klaus Bielefeldt, M.D., Ph.D.
Piush Gupta, M.D.

Peer Review Status: Internally Peer Reviewed
Creation Date: October 2000
Last Revision Date: February 2001

A 58-year-old Caucasian male complained about rash over the legs and lower back, arthralgias and soaking night sweats which had started about one week before his clinic visit. Five weeks prior to presentation, he had been admitted to an outside hospital for evaluation of weakness, dizziness, night-sweats and a 25-pound weight loss. A CT scan had revealed a liver abscess, which was aspirated. A"streptococcus species" was isolated from the aspirate. He was treated with IV ceftriaxone for about 3 weeks and was discharged after resolution of his symptoms.

His past history was significant for chronic alcoholic pancreatitis with pancreatic duct strictures and stones which had been treated with dilation and stone extraction 4 years ago. He had reduced his alcohol consumption since and quit completely 6 months ago. On physical examination, the patient appeared disheveled and ill. He had poor oral hygiene with few remaining, badly decaying teeth . He had RUQ tenderness without rebound or guarding. The liver span was estimated to be around 13 cm in the midclavicular line. He had 1+ pitting edema up to his shins. He had a skin rash that was most prominent over his feet, hands and the sacral area

Based on his history and the physical findings, recurrent hepatic abcesses were suspected. An ultrasound examination demonstrated multiple hypoechoic lesions in the liver measuring up to 4.3x3.3 cm with increased blood flow to the periphery. On contrast-enhanced CT scan, these lesions appeared hypodense. In addition, scattered calcifications in the pancreatic head and body, minimal ascites and portal vein thrombosis with cavernous transformation were noted. Two drains were placed in the largest abscesses in the right and left lobes under ultrasound guidance . Only one organism, streptococcus milleri, was identified in the aspirated material. To further delineta the nature of the skin rash, biopsies were obtained which revealed leucocytoclastic vasculitis.

Discussion:

The two major mechanisms for development of pyogenic liver abscesses are local spread from contiguous infections within the peritoneal cavity or hematogenous seeding of the liver either through the portal vein or hepatic artery. However, in many situation, no obvious cause can be found for the formation of hepatic abscesses. The average patient age is most often between 50-60 years. Biliary disease with cholangitic spread remains the major cause of pyogenic liver abscesses. Typically, multiple abscesses are present in patients with suppurative cholangitis.

The organisms recovered from the liver abscesses are varied and often reflect the origin of the infectious process. With hematogenous spread of infection, a single organism is most commonly isolated, including Staphyllococcus aureus or a streptococcal species such as Streptococcus milleri.

Clinical symptoms and signs can be varied and most patients do not have symptoms directly referable to the right upper quadrant. Fever occurs in upto 90% of patients. Nonspecific symptoms include chills, anorexia, weight loss, nausea and vomiting and malaise.

Laboratory abnormalities are nonspecific with an elevated serum alkaline phosphatase level, which is the single most reliable abnormality for liver abscess. Ultrasonography and computed tomography are the imaging studies of choice. The traetment combines drainage with sufficiently long antibiotic therapy. Percutaneous drainage has virtually replaced open surgical drainage.

The duration of antibiotic therapy may be weeks to months till repeat CT scans show complete resolution of the abscess cavity. An identifiable focus of primary infection should also be addressed when possible. In this case isolation of Streptococcus milleri helped localize the site of infection. The patient underwent removal of his few remaining decaying teeth. The presence of leucocytoclastic vasculitis in this case was an incidental though interesting finding.

References:

1.    Johannsen EC, Sifri CD, Madoff LC: Pyogenic liver abscess. Infectious Disease Clinics of North America. Vol. 14. No.3. September 2000.

2.    Huang CJ, Pitt HA, Lipsett PA. Pyogenic hepatic abscess: Changing trends over 42 years. Ann Surg 1996; 223:600.

3.    Rubin RH, Swartz MN, Malt R. Hepatic abscess: Changes in clinical bacteriologic and therapeutic aspects. Am J Med 1974; 57:601

4.    Robert JH, mirescu D, Ambrosetti P. Critical review of the treatment of pyogenic hepatic abscess. Surg Gynecol Obstet 1992; 174:97