Liver Pathologies Focal PDF

✓Biliary Obstruction Proximal ✓Extrahepatic mass Distal ✓Common duct stricture ✓Passive hepatic congestion Biliary obstruction: Biliary obstruction refers to the blockage of any duct that carries bile from the liver to the gallbladder or from the gallbladder to the small intestine This can...

✓Biliary Obstruction Proximal ✓Extrahepatic mass Distal ✓Common duct stricture ✓Passive hepatic congestion Biliary obstruction: Biliary obstruction refers to the blockage of any duct that carries bile from the liver to the gallbladder or from the gallbladder to the small intestine This can occur at various levels within the biliary system.  Biliary obstruction to the flow of bile may occur within the ducts or secondary to external compression Obstruction could be proximal or distal. Gallstone disease is the most common cause of biliary obstruction. Women are much more likely to develop gallstones Biliary obstruction: Proximal Biliary obstruction proximal to the cystic duct can be caused by: 1.Gallstones 2.Carcinoma of the common bile duct 3.Metastatic tumor invasion of the porta hepatis. Clinically the patient may be jaundiced and may experience pruritus (itching). The liver function test results show an elevation in the direct bilirubin and alkaline phosphatase levels. On a sonogram: ❖carcinoma of the common bile duct appears as a tubular branching with dilated intrahepatic ducts that are best seen in the periphery of the liver. ❖It may be difficult to image a discrete mass lesion. ❖The gallbladder is of normal size. Parallel channel sign or shotgun sing on biliary obstruction secondary to cholangiocarcinom a. Sagittal US scan through the right lobe of the liver shows parallel tubes representing a portal vein (pv) and its accompanying dilated bile duct (bd). A Klatskin tumor (or hilar cholangiocarcinoma) is a cancer of the biliary tree occurring at the confluence of the right and left hepatic bile ducts Obstruction distal to cystic duct may be caused by stones in the common duct. Dilated IHBD (red arrows) are seen as tortuous tubular structures in the liver. Color Doppler makes differentiation of bile ducts (red arrows) and blood vessels (red arrowheads) easy. Biliary Obstruction: Distal A biliary obstruction distal to the cystic duct may be caused by: 1. Stones in the common duct 2. Stricture of the common duct. (may develop from chronic pancreatitis, injury to the bile duct during a laparoscopic cholecystectomy for gallstone disease) Clinically, common duct stones cause: o Right upper quadrant pain o Jaundice o Pruritus Increase in direct bilirubin and alkaline phosphatase levels. On ultrasound examination: Dilated intrahepatic ducts in the periphery of the liver. The size of the gallbladder is variable, but usually small. Gallstones often are present and appear as hyperechoic in gallbladder, with a sharp posterior acoustic shadow Common duct may show shadowy stones within the dilated duct. Passive Hepatic Congestion Passive hepatic congestions develops secondary to congestive heart failure with signs of hepatomegaly. Lab data indicate normal to slightly elevated liver function tests. Transverse and sagittal scans of a patient in right ventricular heart failure show a dilated inferior vena cava (IVC) and hepatic veins (HV). Focal Hepatic Disease Few hepatic lesions have specific sonographic features. Differential considerations include: ▪ Primary tumors ▪ Metastases ▪ Abscesses ▪ Hematomas ▪ Cysts Features most often observed in extrahepatic masses Internal invagination of the liver capsule Discontinuity of the liver capsule Formation of a triangular fat wedge Antero-medial shift of the IVC Anterior displacement of the right kidney Features most often seen in intrahepatic masses Displacement of the hepatic vascular radicles External bulging of the liver capsule Posterior displacement of the IVC  - Simple cyst ✓Cystic lesions - Polycystic liver dis. ✓Pyogenic abscess ✓Hepatic candidiasis ✓Chronic granulomatous disease ✓Amebic abscess ✓Echinococal abscess Cystic Lesions The term hepatic cyst usually refers to a solitary nonparasitic cyst of the liver. It is a fluid-fill mass having an epithelial lining These cysts may be congenital or acquired, solitary or multiple. Patients are often asymptomatic and require no treatment.  Simple Hepatic Cysts Sonographic findings are usually incidental because most patients are asymptomatic. As the cyst grows, it may cause pain or a mass effect, suggesting a more serious condition. It occurs more frequently in females than males. The right lobe is affected twice as often as the left lobe Sonographic appearance Anechoic Thin-walled Ovoid or round Well defined borders Posterior acoustic enhancement If polycystic disease is suspected, check kidneys, spleen and pancreas for associated cysts. Internal echoes may indicate hemorrhage or infection Hepatic Cysts A B A. Congenital liver cysts (arrows) in an asymptomatic patient. Classic signs of a simple cyst are seen including enhancement. B. Simple cyst in the left lobe showing enhancement and a reverberation artifact (arrow). Copyright © 2018 Wolters Kluwer All Rights Reserved Solitary hepatic cyst in the left lobe of the liver shows anechoic, increased through- transmission and well- defined borders. Simple hepatic cyst. A simple liver cyst may appear anechoic with conventional settings (left) and appear with low-level echoes with harmonics (right). Polycystic liver disease: oIs autosomal dominant and affects 1 person in 500. o60 % of patients with polycystic liver disease have associated polycystic renal disease. oThe cyst are small, less than 2 to 3 cm. oCysts within the porta hepatis may enlarge and cause biliary obstruction Gross pathology of polycystic liver disease. There are numerous large cysts throughout the liver parenchyma. Hepatic Cysts C D Congenital Cysts C. Sagittal extended field of view showing polycystic liver disease. Kidneys were normal in this patient. D. Sagittal image of right lobe of liver showing multiple cysts compatible with polycystic liver disease. Patient also had cysts in their kidneys. Copyright © 2018 Wolters Kluwer All Rights Reserved Polycystic liver disease shows multiple cysts throughout the liver and kidney. oAlmost 80% of hepatic abscesses Pyogenic abscess: oIs a pus forming abscess. oThere are many routes for bacteria (most common Escherichia coli) to gain access to the liver: via biliary tree, the PV, hepatic artery, contiguous infection and trauma. Sources of infection include: ❖ Cholangitis ❖ Portal pyemia secondary to appendicitis ❖ Diverticulitis ❖ Inflammatory disease ❖ Colitis ❖ Direct spread from another organ ❖ Trauma with direct contamination ❖ Sickle cell anemia. Clinically the patient presents with: ✓ Fever ✓ Pain ✓ Pleuritis ✓ Nausea, vomiting, and diarrhea. Elevated liver function tests, leukocytosis, and anemia are present. The ultrasound appearance: The size varies from 1 cm to very large. Right lobe in 80% Hypoechoic with round or ovoid margins and acoustic enhancement Complex, with some debris along the posterior margin and irregular and thick walls.  A B A. Sagittal scan of patient with debris-filled pyogenic liver abscess (A). Note acoustic enhancement (arrow) that helped differentiate this from a solid mass. B. Large liver abscess in a patient with cholecystitis Copyright © 2018 Wolters Kluwer All Rights Reserved  C D C. Patient presented with pain, fever, and history of diverticulitis. Sonogram shows complex collection in the left liver lobe compatible with an abscess. Power Doppler demonstrated increased flow around the abscess. D. Multiple gas-forming pyogenic liver abscesses in a patient with a history of diabetes. Notice bright white reflectors (arrows) compatible with gas. This type of abscess is associated with a high mortality rate. Copyright © 2018 Wolters Kluwer All Rights Reserved Amebic Abscess An amebic abscess is a collection of pus formed by disintegrated tissue in a cavity, usually in the liver, caused by the protozoan parasite Entamoeba histolytica. The parasites reach the liver parenchyma via the portal vein The infection is primarily a disease of the colon but can spread to the liver, lungs, and brain. oAmebiasis is contracted by ingesting the parasites in contaminated water and food. oPatients may be asymptomatic or may show gastrointestinal symptoms, pain, diarrhea, leukocytosis and fever The ultrasound appearance of amebic abscess is variable and nonspecific: ✓Round or oval and may have a lack of significantly defined wall echoes. ✓Hypoechoic compared with normal liver parenchyma ✓May show low-level echoes at higher sensitivity. Hepatic Abscess Parasitic Cyst In the right liver lobe (RLL), a 4.5-cm complex cystic mass (M) is detected in a woman who lived for a time in Indonesia. Copyright © 2018 Wolters Kluwer All Rights Reserved Echinococcal Cyst Hepatic echinococcosis is an infectious cystic disease that is common in shepherding areas of the world but is infrequently encountered within the United States.  The disease is spread when food or water that contains the eggs of the parasite is eaten. The eggs are released in the stool of meat-eating animals that are infected by the parasite. Commonly infected animals include dogs, foxes and wolves. For these animals to become infected they must eat the organs of an animal that contains the cysts such as sheep or rodent.  On ultrasound examination, several patterns may occur, from a simple cyst to a complex mass with acoustic enhancement. The shape of the cyst may be oval or spherical, and may have regularity of the walls. Calcifications may occur. Septations are very frequent; and the sonographic appearance have been described as: Honeycomb appearance with fluid collections Water lily sign Cyst within a cyst. Sometimes the liver may contain multiple parent cysts in both lobes of the liver; the cyst with the thick walls occupies a different part of the liver. The tissue between the cysts indicates that each cyst is a separate parent cyst and not a daughter cyst. If a daughter cyst is found, it is specific for echinococcal disease.  E D. Patient from Kenya presented with RUQ pain and hepatomegaly. Sonography demonstrated a large cyst with daughter cysts compatible with an echinococcal cyst. E. Another patient with an echinococcal cyst that is solid and has rim calcifications that is typically seen in inactive cysts. Copyright © 2018 Wolters Kluwer All Rights Reserved  This complex mass found in the right lobe of the liver shows fluid and debris compone nts. Hepatic Candidiasis (fungal infection) Hepatic candidiasis (yeast) is caused by a species of Candida. It usually occurs in immunocompromised hosts, such as patients undergoing chemotherapy, organ transplant recipients, or individuals with human immunodeficiency virus (HIV).  The candidal fungus invades the bloodstream and may affect any organ, with the more perfused kidneys, brain, and heart affected the most. Clinically, the patient may present with nonspecific findings, such as fever and localized pain On ultrasound examination: Candidiasis within the liver may present as multiple small hypoechoic masses with echogenic central cores, referred to as bull’s-eye or target lesions. Other sonographic patterns have been described as “wheel-within-wheel” patterns, or multiple small hypoechoic lesions. Specific diagnosis can only be made with fine-needle aspiration. Fungal Infection— Candidiasis: Microabscesses Multiple small, hypoechoic masses, “wheels within wheels” seen in an immunocompromised patient receiving high-dose chemotherapy  Hepatic tumors A neoplasm is any growth of new tissue, either benign or malignant. A benign growth occurs locally but does not spread or invade surrounding structures. It may push surrounding structures A malignant mass is uncontrolled and is prone to metastasize to nearby structure or distant structures via the bloodstream and lymph nodes. Thus, it is important not only to recognize the tumor mass itself but also to appreciate which structures the malignancy may invade. Benign Hepatic Neoplasm Cavernous hemangioma Liver cell adenoma Hepatic cystadenoma Focal nodular hyperplasia  CAVERNOUS HEMANGIOMA oIs a benign, congenital tumor consisting of large, blood-filled cyst spaces. oIs the most common benign tumor of the liver. oHemangioma enlarge slowly and undergo degeneration, fibrosis and calcification oMore common in Rt than Lt lobe  Lesions are not true neoplasms, as histologically, they are composed of a large network of blood-filled vascular spaces lined with endothelium. Hemangiomas are five times more common in women. Can occur at any age but increase in frequency with age. Most hemangiomas are asymptomatic and found incidentally. Most are solitary but 10% to 20% of patients can have multiple hemangiomas. ULTRASOUND FINDING: Typically hyperechoic results from the wall of multiples blood vessels within them. They are round, oval with well defined walls  B A A. Typical appearance and location of a hemangioma (arrow) in a liver seen under the capsule. This was found incidentally on a gall bladder sonography examination. Interpreting physicians may use the term incidentaloma. B. Three hemangiomas (arrows) were found incidentally on this patient, the larger compatible with a giant hemangioma. Copyright © 2018 Wolters Kluwer All Rights Reserved D E C Same Patient C. A small hemangioma (arrow) is seen in this image.Notice the lack of flow seen with color Doppler. D. A power Doppler image with the image zoomed still demonstrating lackCopyright of flow.© 2018 Wolters Kluwer All Rights Reserved  F G Same Patient F. Giant hemangioma (arrow) found deep in the liver adjacent to the diaphragm. G. Color Doppler does not show any flow inside the mass because the flow within is too slow to be visualized. Copyright © 2018 Wolters Kluwer All Rights Reserved Cavernous hemangioma in this patient shows a well-defined echogenic lesion in the dome of the right lobe of the liver. Color flow is seen within the lesion. The differential considerations include: ❑ hepatocellular carcinoma ❑ liver cell adenoma ❑ focal nodular hyperplasia ❑ solitary metastasis.  LIVER CELL ADENOMA Liver cell adenoma represents normal or slightly atypical hepatocytes The mass is solitary, marginated, and encapsulated. The mass is more commonly seen in females.  There is an increased incidence with use of oral contraceptives and in patients with glycogen storage disease Patients exhibit symptoms. ✓ Palpable mass ✓ Severe right upper quadrant pain when rupture with bleeding occur. If bleeding occurs, the mass may be lucent or of a greater density than the liver.  The mass often looks similar to focal nodular hyperplasia. This lesion has been reported in Type I glycogen storage disease with a 40 % incidence On ultrasound examination: Mass appears solitary or as a multiple hyperechoic solid lesion. The mass increases in size and becomes heterogeneous with hypoechoic foci secondary to necrosis or hemorrhage. Acoustic enhancement is increased. Hepatic adenoma appears as a well-defined lesion with a central hyperechoic area surrounded by a halo.  A B Liver Cell Adenoma (LCA) Same Patient A. Arrow points to an adenoma on a patient who presented with vague RUQ discomfort. B. Color Doppler image showing the vascularity of the mass. The vessels gave the mass a halo effect on gray scale. Copyright © 2018 Wolters Kluwer All Rights Reserved  FOCAL NODULAR HYPERPLASIA This rare, benign tumor is usually discovered by imaging. Is the second most common benign liver mass after hemangioma. The difference between liver cell adenoma an FNI is the absence of bile ducts or Kupffer cells. This tumor is more commonly seen in females