75 Focal Cystic Lesions of the Liver

CLINICAL IMAGAGINGAN ATLAS OF DIFFERENTIAL DAIGNOSIS

EISENBERG

DR. Muhammad Bin Zulfiqar PGR-FCPS III SIMS/SHL

• Fig GI 75-1 Hepatic cysts. Contrast CT scan shows multiple, homogeneous, rounded, well-defined, non-enhancing cystic lesions (arrows), which are consistent with simple bile duct cysts.136

• Fig GI 75-2 Differentiation between hepatic cyst and metastasis. (A) T2-weighted MR image in a patient with a history of colon carcinoma shows two high-signal-intensity lesions (arrows) in segment 1 of the liver. (B) On a heavily T2-weighted image, only the smaller lesion (arrowhead) continues to have the signal intensity of fluid. Therefore, the larger lesion represents a metastasis and the smaller lesion represents a simple bile duct cyst.136

• Fig GI 75-3 Polycystic disease. (A) Contrast CT scan shows multiple non-enhancing hepatic and renal cysts (arrowheads). (B) In another patient, a contrast T1-weighted MR image shows renal cysts (arrows) and the typical MR imaging appearance of hepatics cysts as homogeneous masses with well-defined borders and no enhancement of walls or contents.136

• Fig GI 75-4 Bile duct hamatoma. (A) Contrast CT scan shows numerous non-enhancing cystic lesions scattered throughout the liver of this asymptomatic woman. (B) In another patient, a T2-weighted MR image shows multiple, small (<1.5 cm diameter) hyperintense nodules consistent with biliary hamartomas.136

• Fig GI 75-5 Caroli's disease. Contrast CT scan shows saccular dilatation of the biliary tree (arrowhead) with enhancement of central portal vein radicals (arrows), producing the central dot sign.136

• Fig GI 75-6 Undifferentiated embryonal sarcoma. (A) Contrast CT scan shows a 10-cm cystic lesion in the right lobe of the liver. Note the septa and calcifications (arrow) within the mass. (B) In a different patient, a delayed-phase contrast T1-weighted MR image shows heterogeneous enhancement of the solid portions of the lesion (arrowhead), which were hyperintense relative to normal liver on T2-weighted images.136

• Fig GI 75-7 Biliary cystadenoma. (A) Contrast CT scan shows a 12-cm multiseptated cystic lesion in the right lobe of the liver. Note the focal papillary excrescence (arrowhead). (B) In a different patient, a contrast T1-weighted MR image shows a multiloculated mass with enhancement of the capsule and septa.136

• Fig GI 75-8 Cystic hepatocellular carcinoma. Contrast CT scan shows an ill-defined cystic mass in the right lobe of the liver. On this arterial-phase image, a small hypervascular nodule is seen at the periphery of the mass (arrowhead). Note the indirect signs of liver cirrhosis: atrophy of the right hepatic lobe, hypertrophy of the caudate lobe, contour irregularities, and ascites.136

• Fig GI 75-9 Cystic metastases. (A) Contrast CT scan in a patient with metastatic breast cancer shows a cystic lesion with peripheral enhancement (arrows). (B) In another patient who had ovarian cancer, there is a 7-cm elliptical cystic lesion (arrow) on the surface of the liver.136

• Fig GI 75-10 Pyogenic abscesses. Contrast CT scan shows a large cystic liver mass consisting of a confluent cluster of numerous tiny hepatic abscesses.136

• Fig GI 75-11 Amebic abscess. Contrast CT scan shows a cystic lesion with high attenuation of the surrounding normal liver parenchyma (arrows) due to hyperemia (double target sign).136

• Fig GI 75-12 Hydatid cyst. (A) Contrast CT scan shows two cystic lesions with subtotally calcified walls (arrows) in the liver of a sheep raiser. (B) T2-weighted image in a different patient shows a solitary hyperintense lesion in the right lobe of the liver. Note the internal calcifications (arrowheads) and the hypointense pseudocapsule (arrows).136

• Fig GI 75-13 Hematoma. (A) Contrast CT scan in an assault victim shows a low-attenuation parenchymal hematoma in the posterior segment of the right hepatic lobe, with small coexisting irregular liver lacerations (arrows). (B) Contrast T1-weighted MR image in a young woman shows a “cystic” mass (arrows) in the right hepatic lobe with coexistent acute subcapsular hemorrhage (arrowheads), which proved to be a bleeding hepatocellular adenoma.136

• Fig GI 75-14 Biloma. Contrast CT scan shows three intrahepatic collections (arrows) without evidence of septa, capsules, or calcifications. This appearance is compatible with bilomas in this young man who experienced biliary leakage after a severe motor vehicle accident.136

• Fig GI 75-15 Intrahepatic pancreatic pseudocyst. (A) Contrast CT scan obtained 3 weeks after an episode of acute pancreatitis shows multiple intraperitoneal pseudocysts and a 5-cm cystic lesion in the left lobe of the liver (arrows). The lesion is well defined due to the presence of a capsule and has homogeneous fluid attenuation, findings that in this clinical context are pathognomonic for an intrapancreatic pseudocyst. (B) T2-weighted MR image in another patient after an episode of necrotizing pancreatitis shows a homogeneous hyperintense pseudocyst (arrows) along the right lobe of the liver.136