Benign hepatic masses

benign hepatic masses

1. BENIGN HEPATIC MASSES DR. DEVKANT LAKHERA

2. Imaging techniques Primary screening : Ultrasonography: Gray -scale and color Doppler sonography Triple phase Multidetector computed tomography (MDCT) : Gold standard Unenhanced : Attenuation differs Calcification / cystic component / fat / haemorrhage

3. Triple phase CT Normal parenchyma - 80% by the portal vein and only for 20% by the hepatic artery, so it will enhance in the portal venous phase. Arterial 18-30 sec 3-5 ml /sec

4. arterial phase   hypervascular tumors will enhance portal venous phase   hypovascular tumors are detected, when the normal liver parenchyma enhances maximally. equilibrium phase  tumors become visible, delayed washout or rapid washout

5. Arterial phase hypervascular lesions best at 35 sec For arterial phase imaging the best results are with an injection rate of 5ml/sec. 

6. Angiography Magnetic resonance imaging (MRI) : Dynamic Contrast enhanced Nuclear medicine: positron emission tomography (PET), red blood cells (RBCs) tagged with technetium Tc 99m;

7. Liver lesion characterization Fat Haemorrhage (Adenoma, HCC) Calcification (Met colon, FLC, Cholangiocarcinoma, hemangioma ) Capsule (HCC > Adenoma) Capsular retraction ( Cholangio mc) Scar (FNH/FLC/ Hemangioma ) Size Age Cirrhosis Enhancement morphology

8. Hypervascular benign lesions Adenoma FNH Hemangioma Malignant : - HCC/ Mets (Breast/ Sarcoma) Hypovascular lesions – Malignant 10% HCC / met / cholangiocarcinoma

9. Types of masses Cellular origin Infective Hepatocyte Adenoma Focal Nodular Hyperplasia ( FNH ) Hepatocellular Nodules in Cirrhosis. Nodular Regenerative Hyperplasia ( NRH ). Mesenchymal Cells • Mesenchymal hamartoma • Hemangioma • Infantile hemangioendothelioma • Lymphangioma •Lipoma/ angiomyolipoma / myelipoma • Leiomyoma / Fibroma Bile Duct Epithelium • Hepatic cysts • Polycystic liver disease/congenital hepatic fibrosis • Biliary cystadenoma • Bile duct adenoma

10. Hepatocellular adenoma Rare benign tumor (younger age group compared to FNH) Females (90%). Pain abdomen Predisposing factors - OCPs, steroids and GSDs.

11. ULTRASOUND Typically - Large hyperechoic lesion with central anechoic areas. Variable degrees of hemorrhage, necrosis & fat. Calcification rare. Some intratumour veins may be present

12. Characteristic appearance Solitary (80%) and large at time of presentation (8-10cm) Clear border No capsule (fibrous capsule in some cases) Core - bleeding, necrosis, scar tissue Contains-fat & glycogen

13. CT scan Hypodense mass. Hyper attenuation areas in case of ruptured. Calcification is rare. Subcapsular location 75 %

14. MRI Hyper to isointense on T1 Hypo to hyperintense on T2 Hemorrhagic tumor hyperintense on T1 & T2

15. Focal Nodular Hyperplasia Second common benign lesion. Female >> male. 8:1 Reactive change (hyperplastic) to abnormal circulation. Well defined lesion characterized by a central fibrous scar .

16. Characteristic appearance Well-demarcated, solitary mass without a capsule. (<5 cm) Often located beneath the surface of liver (subcapsular). In central scar - feeding arteries, draining veins connecting to hepatic vein. Necrosis and hemorrhage usually not seen.

17. USG well-demarcated, hypoechoic mass that is homogeneous except for a central scar Colour doppler-central vascularity.

18. CT scan Homogenous hypodense mass Central scar showing more marked hypodensity

19. Arterial phase- brisk homogenous enhancement. Portal phase-early wash out. Delayed phase-barely visible with enhancing scar D/D - Fibrolamellar carcinoma – larger 12cm, non enhancing scar, calcification, mets

20. MRI Iso - hypointense on T1. Hyper - isointense on T2. Central scar Hypointense on T1. Hyperintense on T2.

21. Nodular regenerative hyperplasia Diffuse nodularity of the liver produced by many regenerative nodules that are not associated with fibrosis. S een in myeloprolifertive , lymphoproliferative and collagen vascular disease Nodular transformation of the liver, diffuse nodular hyperplasia and noncirrhotic nodulation

22. Ranges of appearance – Normal liver to multiple focal nodules of varying attenuation (primarily hypodense) E nhance on arterial phase I mperceptible on portal phase

23. MRI- Isointense with hyperintense foci on T1 Hypo on T2(opposite to HCC).

24. Hemangioma Most common primary liver tumor. All age groups. Females >> males. Size less than 1 cm to 30 cm (giant hemangioma ).

25. Characteristic appearance Usually solitary. Well circumscribed. Not encapsulated. Various degenerative changes are seen in its centre. Necrosis, scarring, hemorrhage & calcification.

26. USG typically hyperechoic , well demarcated with faint acoustic enhancement No internal vascularity

27. slowly perfused vascular space

28. Dynamic vascular enhancement pattern may vary with the size of the lesions d/d hypervascular tumor

29. MRI Hypointense on T1. Hyperintense on T2. In T2 signal intensity is higher than that of spleen. T1 C + ( Gd )

30. Hepatic cyst (bile duct cyst) Incidental lesions Vary in number and size. Cuboidal (bile duct) epithelium. Compressive symptoms (massive).

31. CT Simple cyst No mural enhancement Complex cyst – Debris, septation , complex internal contents

32. Biliary cystadenoma Uni or Multilocular cystic liver mass. Adults, Females >> males. Malignant transformation to cystadenocarcinoma is not uncommon. Clinical presentation Chronic abdominal pain. Originates from bile duct.

33. CT UECT – well defined hypodense lesion. Wall and internal septations are often visualized (differentiate from simple cyst). CECT – cyst wall and soft tissue component typically enhance.

34. Bile duct hamartoma / von Meyenburg complexes  multiple bile duct hamartomas F ailure of involution of embryonic bile duct Inumerable cystic lesions <5mm in diameter

35. Multiple tiny cystic lesions in both lobes of liver

36. Angiomyolipoma Rare benign tumor. Composed of mature fat, blood vessels and smooth muscle cells. It is not capsulated. Tuberous sclerosis - association of hepatic angiomyolipoma.

37. usg Circumscribed heteroechoic lesion./hyperechoic

38. CT Solid mass containing markedly hypodense area. Arterial phase- partially enhancement often with visualization of large central vessels.

39. MRI Hyperintense on both T1 & T2. Decreased intensity with fat suppression .

40. Infantile hemangioendothelioma Common infant benign lesion. Resembles capillary hemangioma seen in infantile skin and mucosa. With in 6 months of birth. Solitary mass but may be multifocal. Typically large (1-20 cm).

41. ct Hypodense area. 16%- calcification and hemorrhage. CECT – similar to that of cavernous hemangiomas . MRI-Resemble those of hepatic hemangioma .

42. Hepatic abscess Localized collections of necrotic inflammatory tissue Pyogenic, amoebic and fungal. (parasitic mc in india ) Via – portal vein, hepatic artery or bile duct. Solitary or multiple. Bacterial and fungal abscesses -multiple Amoebic abscesses - frequently single .

43. USG spherical, lobulated V ariable appearance (amount of liquefaction) Variable mural thickness wall typically is irregular and hypoechoic. S eptations and internal debris is present

44. CT peripherally enhancing, centrally hypoattenuating lesions with septations and debris

45. Pyogenic liver abscess Double target Cluster sign

46. Amoebic – CECT- enhanced mural structure with hypodense area at its lateral side owing to the presence of oedema .

47. Hydatid cyst Parasitic infection Echinococcus granulosus pericyst : composed of inflammatory tissue of host origin exocyst endocyst :  scolices (the larval stage of the parasite) and the laminated membrane are produced here

48. USG findings An anechoic cyst except for hydatid "sand“ A multi septate cyst with daughter cysts & echogenic material between cysts (characteristic) "Water lily" sign: A cyst with a floating, undulating membrane with a detached endocyst A densely calcified mass

49. Multiseptate cyst with "daughter" cysts and echogenic material between cysts

50. CT AND MRI Thick walled cystic lesions with internal round periphery daughter cysts. Attenuation and signal intensity in mother cyst is more than daughter cyst. Curvilinear ring-like calcification

51. Axial CECT shows large cystic mass with partially calcified wall. Note hypodense septa and floating debris ( scolices ).

52. CE 1 uniformly anechoic cyst with fine echoes settled in it representing hydatid sand CE 2 cyst with multiple septations giving it multivesicular appearance or rosette appearance or honeycomb appearance with unilocular mother cyst this stage is the active stage of the cyst CE 3 unilocular cyst with daughter cysts with detached laminated membranes appearing as  water lily sign this is the transitional stage of the cyst CE 4 mixed hypo- and hyperechoic contents with absent daughter cysts ; these contents give an appearance of a ball of wool ( ball of wool sign ) indicating the degenerative nature of the cyst CE 5 arch-like thick partially or completely calcified wall this stage of cyst is inactive and infertile

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