Adenom der Gallenblase
Pyloric-type
gallbladder adenoma: ultrasound, CT and MRI findings. Sonography showed a large (maximum diameter 3.6 cm) non-mobile homogeneous intraluminal mass (arrowheads), approximately isoechoic with the liver, overlying the continuous, non-thickened gallbladder wall (thin arrows).
Pyloric-type
gallbladder adenoma: ultrasound, CT and MRI findings. The intraluminal gallbladder mass (arrowheads) did not show diffusion restriction at b 800 (d) with corresponding apparent diffusion coefficient (ADC) value 2.1x10-3 mm2/s (e).
Pyloric-type
gallbladder adenoma: ultrasound, CT and MRI findings. Portal venous (d,e) showed persistent moderate and homogeneous enhancement of the gallbladder mass (arrowheads); normally enhancing, thin and continuous gallbaldder wall (thin arrows), nonenhanced duodenal lipoma (thick arrow).
Pyloric-type
gallbladder adenoma: ultrasound, CT and MRI findings. Portal venous (d,e) and equilibrium phase (f) showed persistent moderate and homogeneous enhancement of the gallbladder mass (arrowheads); normally enhancing, thin and continuous gallbaldder wall (thin arrows).
Pyloric-type
gallbladder adenoma: ultrasound, CT and MRI findings. The intraluminal gallbladder mass was moderately and homogeneously enhanced in the arterial phase (b, c with subtraction) after intravenous gadolinium contrast (gadobutrol).
Pyloric-type
gallbladder adenoma: ultrasound, CT and MRI findings. The intraluminal gallbladder mass was moderately and homogeneously enhanced in the arterial phase (b, c with subtraction) after intravenous gadolinium contrast (gadobutrol).
Pyloric-type
gallbladder adenoma: ultrasound, CT and MRI findings. The intraluminal gallbladder mass (arrowhead) showed low-to-intermediate precontrast T1 signal intensity.
Pyloric-type
gallbladder adenoma: ultrasound, CT and MRI findings. MR-cholangiopancreatography images showed small filling defects (arrows) in the non-dilated common bile duct, consistent with sludge, blood clots or fragments of the gallbladder mass (arrowheads).
Pyloric-type
gallbladder adenoma: ultrasound, CT and MRI findings. The intraluminal gallbladder mass (arrowheads) did not show diffusion restriction at b 800 (d) with corresponding apparent diffusion coefficient (ADC) value 2.1x10-3 mm2/s (e).
Pyloric-type
gallbladder adenoma: ultrasound, CT and MRI findings. T2-weighted images (a-b, fat-suppressed c) confirmed intraluminal gallbladder mass (arrowheads) with low signal intensity, overlying the thin, continuous gallbladder wall (thin arrows).
Pyloric-type
gallbladder adenoma: ultrasound, CT and MRI findings. The gallbladder intraluminal mass (arrowheads) was seen overlying the continuous, non-thickened gallbladder wall (thin arrows), showed lobulated margins and appeared approximately isoechoic with the liver.
Pyloric-type
gallbladder adenoma: ultrasound, CT and MRI findings. T2-weighted images (a-b, fat-suppressed c) confirmed intraluminal gallbladder mass (arrowheads) with low signal intensity, overlying the thin, continuous gallbladder wall (thin arrows).
Pyloric-type
gallbladder adenoma: ultrasound, CT and MRI findings. T2-weighted images (a-b, fat-suppressed c) confirmed intraluminal gallbladder mass (arrowheads) with low signal intensity, overlying the thin, continuous gallbladder wall (thin arrows).
Pyloric-type
gallbladder adenoma: ultrasound, CT and MRI findings. Portal venous phase images (d,e) showed moderately enhancing intraluminal gallbladder mass (arrowheads) overlying the normal gallbladder wall (thin arrows). Note normal pancreatic enhancement, duodenal lipoma (thick arrow).
Pyloric-type
gallbladder adenoma: ultrasound, CT and MRI findings. Portal venous phase images (d,e) showed moderately enhancing intraluminal gallbladder mass (arrowheads) overlying the normal gallbladder wall (thin arrows). Note normal pancreatic enhancement, peripancreatic oedema (*).
Pyloric-type
gallbladder adenoma: ultrasound, CT and MRI findings. Moderately vascularised intraluminal mass (arrowheads) with vascular pedicle in the arterial-dominant (b,c) phase. Note normal thickness and enhancement of gallbladder wall (thin arrows), duodenal lipoma (thick arrow)
Pyloric-type
gallbladder adenoma: ultrasound, CT and MRI findings. Post-contrast images showed moderately vascularised gallbladder intraluminal mass (arrowheads) with vascular pedicle in the arterial-dominant (b,c) phase. Note continuous, normally enhancing gallbladder wall (thin arrows), peripancreatic oedema (*).
Pyloric-type
gallbladder adenoma: ultrasound, CT and MRI findings. The intraluminal gallbladder mass (arrowhead) overlying the non-thickened wall (thin arrow) showed solid attenuation values (28-30 Hounsfield units) on unenhanced scans. Note fatty liver, peripancreatic oedema (*).
Pyloric-type
gallbladder adenoma: ultrasound, CT and MRI findings. Portal venous (d,e) and equilibrium phase (f) showed persistent moderate and homogeneous enhancement of the gallbladder mass (arrowheads); normally enhancing, thin and continuous gallbaldder wall (thin arrows).
Gallbladder adenomas are uncommon gallbladder polyps that, although benign, have a premalignant behavior.
Terminology
As the distinction of adenomas and intracholecystic papillary-tubular neoplasms (ICPN) is not entirely clear, with important overlap between both entities, some authors have proposed that all the adenomas over 1 cm should be grouped under the ICPN terminology . A note is made that the last WHO classification is from 2010, therefore, proceeding these publications.
Epidemiology
Adenomas make 4% to 7% of all gallbladder polyps . They are incidentally found in about 0.5% of the gallbladder specimens .
There is a 2.4:1 female-to-male prevalence ratio .
Associations
Increased prevalence of gallbladder and biliary tract adenomas occurs in :
Pathology
Macroscopic appearance
They are polypoid structures projecting into the gallbladder lumen usually measuring less than 2 cm in size, and showing either a sessile or pedunculated appearance. In about 10% of the cases, adenomas are multiple .
Microscopic appearance
Gallbladder adenomas are classified in :
- tubular adenomas
- the most common
- composed by pyloric-type glands: cuboidal or columnar cells containing vesicular or hyperchromatic nuclei and covered by biliary epithelium
- or by intestinal-type glands: with pseudostratified columnar epithelium covered by biliary epithelium
- papillary adenomas
- papillary structures lined by cuboidal or columnar cells
- tubulopapillary adenomas
- subtype characterized when both the tubular glands and the papillary formations each corresponds to more than 20% of the tumor
Radiographic features
There are no reliable imaging features to distinguish adenomas from gallbladder adenocarcinomas . They might be associated with gallstones or features of chronic cholecystitis.
Ultrasound
Adenomas are usually solitary gallbladder wall lesions that can have a sessile, pedunculated, or polypoid appearance.
- usually hypoechoic with no posterior acoustic shadowing
- variable size, usually between 5 mm to 20 mm
- may have a lobulated or cauliflowerlike contour
- in the pedunculated lesions, the stalk might be difficult to visualize and might require changes in the patient decubitus
- internal vascularity at color Doppler may be demonstrated
- focal gallbladder wall thickening adjacent to the polyp is a worrisome feature concerning for malignancy
- CEUS: enhancement is seen in the arterial phase
CT
They might be distinguished as small hypodense intraluminal gallbladder lesions that demonstrate enhancement .
Treatment and prognosis
Gallbladder adenomas are usually managed surgically. Please refer to the parental article on gallbladder polyps for guidelines on when followup or surgery should be considered.
Differential diagnosis
- gallbladder adenocarcinoma
- virtually impossible to confiently differentiate on imaging alone
- gallbladder metastasis
Siehe auch:
- Adenomyomatose der Gallenblase
- Polypen der Gallenblase
- tubuläres Adenom der Gallenblase Pylorusdrüsentyp
und weiter:
Assoziationen und Differentialdiagnosen zu Adenom der Gallenblase:
