Liver Pathology Part II PDF

 The cyst may be congenital or acquired, solitary or multiple. Differential diagnosis of liver cyst includes: Simple cyst Cystic lesions Polycystic liver disease Hydatid cyst...

 The cyst may be congenital or acquired, solitary or multiple. Differential diagnosis of liver cyst includes: Simple cyst Cystic lesions Polycystic liver disease Hydatid cyst Cystic tumors Abscess Simple hepatic cysts ​Simple hepatic cyst is usually incidental because most patients are asymptomatic. As the cyst grows, it may cause pain or a mass effect to suggest a more serious condition, such as infection, abscess, or necrotic lesion. Hepatic cysts occur more often in females than in males. Sonographic findings of simple (benign) cyst: Thin wall, well-defined borders, and anechoic, with posterior enhancement and edge shadowing. Complications, such as hemorrhage, may occur and cause pain. Calcification may be seen within the cyst wall and may cause shadowing. ​A, Solitary hepatic cyst in the left lobe of the liver shows increased through-transmission and well- defined borders. B, Liver cyst appears complex secondary to the hemorrhage.  Polycystic liver disease Polycystic liver disease is inherited in an autosomal dominant pattern. 50% to 74% of patients with polycystic renal disease have hepatic cysts. The cysts are small, less than 2 to 3 cm, and multiple throughout the hepatic parenchyma. Liver function tests are usually normal. Sonographic findings: The cysts generally present as anechoic, well- defined borders with acoustic enhancement. ​A, Gross pathology of polycystic liver disease. There are numerous large cysts throughout the liver parenchyma. B–D, Images of a liver parenchyma filled with multiple cystic lesions in patients with hepatic polycystic disease.  Infectious disease of the liver Hepatic abscesses occur most often as complications of biliary tract disease, surgery, or trauma. The following three basic types of abscess formation occur in the liver: intrahepatic, subhepatic, and subphrenic. Pyogenic abscess A pyogenic abscess is a pus-forming abscess. Can result from the spread of infection from inflammatory conditions such as appendicitis, and cholecystitis. Occur commonly in the right lobe of liver  Clinically the patient presents with fever, nausea, vomiting, RUQ pain, and hepatomegaly. Elevated liver function tests, and leukocytosis are present. The most frequent organisms are Escherichia coli and anaerobes. Aspiration is needed to confirm diagnosis Sonographic findings: The abscess may be hypoechoic with acoustic enhancement It may be complex, with irregular thick walls. If gas is present, it can be hyperechoic with dirty shadowing or ring-down artifact. Pyogenic liver abscesses  Occurs when a parasite (Entamoeba histolytica) from the intestines, reach the liver via the portal vein. Differentiation of a pyogenic abscess from an amebic abscess is difficult. If a patient has travelled out of the United States, an amebic abscess may be the correct diagnosis. Amebic abscess Aspiration may be required for diagnosis Symptoms and findings: Right upper quadrant pain, fever, and bloody diarrhea. Leukocytosis and elevated liver function tests Sonographic features: The abscess is hypoechoic with low- level echoes (complex mass), may be round or oval and lack defined wall echoes, have some acoustic enhancement. Typically occurs in right lobe (dome), contiguous with the liver capsule Amebic abscess is a complex lesion, usually in the right lobe of the liver  ​Hepatic candidiasis is caused by a species of Candida. It usually occurs in immunocompromised hosts, such as patients undergoing chemotherapy, organ transplant recipients, or Fungal Abscess individuals with human immunodeficiency virus (HIV) (Candidiasis) infection Clinically: RUQ pain, fever, and hepatomegaly. Specific diagnosis can only be made with needle aspiration Fungal abscess Bull’s-eye (target) lesions - shows diffuse, homogeneous, hypoechoic foci The appearance of these lesions can change over the course of the disease process.  Echinococcal cyst (​Hydatid cyst) Develop from a parasite referred to as Echinococcus granulosus. This parasite lives in dog feces. Food contaminated (with egg) by infected feces consumed indirectly by sheep, cattle, goat, and possibly humans. Seldom encountered within the United States. It has the highest incidence in countries in which sheep herding is common. The parasite moves from the bowel through the portal vein to enter the liver (the most common site for growth). Clinically, low-grade fever and right upper quadrant tenderness. Surgical resection or medical treatment may be used to manage a hydatid liver cyst. Sonographic appearance can be variable. Simple cyst can contain some debris. Honeycomb appearance Floating membranes can be seen within the cyst (water lily sign). Hydatid cysts may also appear as cysts within a cyst. The mass may also contain some elements of dense calcification.  Schistosomiasis Schistosomiasis is a parasitic infections in humans. Endemic in tropical zones around the world. Eggs reach the liver through the portal vein resulting in periportal fibrosis. The intrahepatic portal veins occlude resulting in portal hypertension. Sonographic findings: Occluded intrahepatic portal veins Thickening and increased echogenicity of the portal vein walls Secondary signs of portal hypertension Sonographic features of periportal fibrosis in schistosomiasis  Present as small calcifications in Granulomas the liver and spleen. Caused by Histoplasmosis or Tuberculosis infection. Benign hepatic tumors Cavernous hemangioma Focal nodular hyperplasia (FNH) Hepatic Lipoma Hepatic adenoma Hepatic Hematoma  Cavernous hemangioma A cavernous hemangioma is the most common benign neoplasm of the liver More common in women. Patients are usually asymptomatic (incidentally detected). Hemangiomas consist of multiple vascular channels (blood-filled spaces) that create multiple sonographic interfaces which give this mass its characteristic hyperechoic appearance. May enlarge as a result of estrogen stimulation during pregnancy.   Sonographic findings: They are found in the subcapsular hepatic parenchyma or in the posterior right lobe The lesions is well-defined borders, round or oval, homogeneous, hyperechoic mass that is usually less than 3 cm in size with acoustic enhancement There is low-velocity blood flow that is too low to be detected by color Doppler. This diminished blood flow pattern may help to distinguish the hemangioma from a malignant mass. Cavernous hemangioma. The appearance is typically a homogeneous, hyperechoic mass that is usually less than 3 cm in size  ​Focal nodular hyperplasia (FNH) is the second most common benign liver mass after hemangioma. It typically contains a central scar that Focal nodular is not always detected with hyperplasia sonography. Patients who have FNH are most often (FNH) asymptomatic. Hormonal influence may be present as FNH is found more commonly in women under 40 than in men.  FNH generally demonstrate a solitary, well-circumscribed (isoechoic, hyperechoic, or hypoechoic) a non-encapsulated multinodular mass and many have a central scar. The size of the mass is usually less than 5 cm. FNH has been referred to as a “stealth lesion” because it may be difficult to Sonographic finding: identify secondary to its slight sonographic disparity from normal liver parenchyma. Central scar will appear as an hyperechoic or hypoechoic linear structure within the mass and will reveal hypervascularity with color Doppler imaging Hepatic Lipoma Hepatic lipomas are extremely rare fatty tumors. Patients are asymptomatic Sonographic appearance is that of a hyperechoic mass with propagation speed artifact  Hepatic adenoma Is a rare benign liver tumor. It is often associated with the use of oral contraceptives. Also found in men taking anabolic steroids. Patients are asymptomatic. Sonographic appearance: This lesion is usually hyperechoic with a central hypoechoic area caused by hemorrhage. Hyperechoic mass with a central hypoechoic area caused by hemorrhage. Hepatic Hematoma Hepatic hematomas can be the results of trauma or surgery. Hematomas can be located intrahepatic or subcapsular. Hematomas can appear solid or complex depending upon their age. Initial hemorrhage appears echogenic, and over time as it resolves it will appear cystic or complex.  Malignant hepatic neoplasms Hepatocellular Carcinoma Metastatic liver disease  Hepatocellular Carcinoma Hepatocellular carcinoma (Hepatoma) is the most common primary malignancy of the liver. HCC is most often seen in men and frequently accompanied by cirrhosis or chronic hepatitis. Clinically: abnormal LFT’s, signs of cirrhosis, unexplained weight loss, hepatomegaly, fever and/or a palpable mass. A tumor marker for HCC is serum alpha-fetoprotein (AFP). Most patients with HCC will have an elevated AFP.  Sonographic findings HCC may appear as a solitary, small hypoechoic mass or as a heterogeneous masses scattered throughout the liver. A hypoechoic halo may be noted around the hepatoma.  Metastatic tumors are the most common form of neoplastic involvement of the liver. The malignant cells enter the liver through the portal veins or lymphatic Hepatic channels. The most common primary cancers Metastasis that metastasize to the liver is from gastrointestinal, breast or lung cancer. Clinical features: weight loss, jaundice, RUQ pain, hepatomegaly, and ascites. LFT’s will be abnormal as well.  Sonographic findings metastatic liver disease is variable often depending upon the location of the primary cancer. It may be hyperechoic, hypoechoic, Bull's eye or target metastases, calcified metastases, cystic metastases. May appear as one mass, several masses, or diffuse Bull's eye or target metastases involvement.  Lymphoma ​Lymphomas are malignant neoplasms The two main disorders, Hodgkin’s lymphoma and non-Hodgkin’s lymphoma. The presence of splenomegaly or retroperitoneal nodes may help confirm the diagnosis of lymphadenopathy.  Sonographic findings:  Well defined small hypoechoic nodules  Diffuse infiltrative disease  Abdominal lymphadenopathy  Orthotopic liver transplant - the recipient liver and gallbladder are excised and the cadaveric liver is transplanted. Heterotopic liver transplant - the recipient liver remains in place and a portion of donor liver is transplanted. Liver It is the most common type of liver transplantation. liver transplantation is performed to eliminate Transplantation irreversible disease. Indications for transplantation in adults: Cirrhosis Indications for transplantation in children: Biliary atresia The most common complication of liver transplantation are hepatomegaly and infection The arterial and venous anastomosis for orthotopic liver transplant require at least three anastomosis: 1. The extrahepatic portal vein 2. Hepatic artery 3. Suprahepatic IVC 4. Infrahepatic IVC may be necessary Sonography is not a valuable tool for confirmation of liver transplant rejection (not sensitive for diagnosis). Biopsy is the tool used for diagnosis of liver transplant rejection