Gallbladder cancer revisited: the evolving role of a radiologist

Abstract

Gallbladder cancer is the most common malignancy of the biliary tract. It is also the most aggressive biliary tumor with the shortest median survival duration. Complete surgical resection, the only potentially curative treatment, can be accomplished only in those patients who are diagnosed at an early stage of the disease. Majority (90%) of the patients present at an advanced stage and the management involves a multidisciplinary approach. The role of imaging in gallbladder cancer cannot be overemphasized. Imaging is crucial not only in detecting, staging, and planning management but also in guiding radiological interventions. This article discusses the role of a radiologist in the diagnosis and management of gallbladder cancer.

Figure 1.

Predisposing factors. (a, b) Porcelain GB. (a) Sagittal multiplanar CT image showing thin incomplete calcification of GB wall (arrow heads) with mass in the neck region (arrow). (b) Sagittal MIP image of another patient with GBC showing complete intramural GB wall calcification (black arrowheads) and cholelithiasis (white arrow). Selective mucosal & incomplete calcification have higher risk of malignancy than the complete type. (c, d) Primary sclerosing cholangitis. (c) Coronal MRCP image showing multiple short segment strictures (white arrowheads) alternating with dilated IHBR involving both lobes with a tight stricture of left hepatic duct (arrow) suggestive of sclerosing cholangitis. (d) Axial CT image showing a mass replacing the GB with infiltration into the adjacent liver (arrows) and ascites (asterisk). GBC, gallbladder cancer; IHBR, intrahepatic biliary radicals; MIP, maximum intensity projection; MRCP,magnetic resonance cholangiopancreatography.

Figure 2.

Mass replacing the gallbladder. (a) USG of a patient of GBC showing a heteroechoic mass replacing the GB (asterisk) with a large calculus within (arrow). (b, c) Axial CT scans in arterial (b) and venous (c) phases showing a large heterogeneously enhancing mass (asterisk) completely replacing the GB and infiltrating the liver parenchyma. GBC, gall bladder cancer; USG, Ultrasonography.

Figure 3.

MRI of mass replacing the gallbladder: Axial T₁W (a), T₂W fat saturated (b), diffusion weighted (c) and contrast-enhanced arterial (d), venous (e) and delayed (f) phase MR images showing a large gallbladder mass (asterisk) infiltrating liver and appearing hypointense on T₁W, hyperintense on T₂W, and showing restriction of diffusion and heterogeneous contrast enhancement. A large portocaval lymph node is noted (arrow).

Figure 4.

Asymmetric wall thickening: Ultrasonography (a) and CT scan (b) images showing asymmetric wall thickening in the fundus (white arrow) and body (black arrow) of gallbladder. Calculus is seen in the neck region (arrow head). Thickening which is asymmetric, nodular and >1 cm thick suggests malignancy.

Figure 5.

Intraluminal polypoidal mass. Ultrasonography (a) and CT scan (b) showing a hypoechoic and enhancing polypoidal mass (arrow) in the lumen of gallbladder. This variety has the best prognosis.

Figure 6.

Multifocal disease: Axial (a, b) and sagittal (c) CT images showing separate soft tissue masses in the fundus (white arrow) and neck (black arrow) of GB, suggesting multifocal disease. Hyperdense calculi are also seen within (arrow heads). GB, gall bladder.

Figure 7.

Local invasion. (a) Axial CT scan image showing a polypoidal GB mass (asterisk) with adventitial invasion (nodular surface – arrow). (b) Axial CT scan image showing liver infiltration (arrow) of a GB mass (asterisk). (c, d) Vascular invasion. Axial CT images in arterial (c) & venous (d) phases showing GB mass involving common hepatic artery (white arrow) & main portal vein (black arrow). GB, gallbladder.

Figure 8.

Local invasion: (a–c): Axial CT images of different patients of GBC showing invasion of duodenum (arrow in a), hepatic flexure (arrow in b) and abdominal wall (arrow in c). Air foci are seen in the mass in a, b suggesting fistula. d: Coronal T₂W MR image showing invasion of gastric antrum and duodenum (arrows) by GB mass (asterisk). (e, f) Perineural invasion. Axial (e) and coronal (f) venous phase CT images of a patient with GBC showing a mantle of soft tissue along the proper hepatic and common hepatic artery (hepatic plexus – arrow in e), celiac axis (black arrow in f) and SMA (white arrow in f). GBC, gallbladder cancer; SMA, superior mesenteric artery.

Figure 9.

Bile duct invasion: (a–d) By primary mass. (a, b) Axial CT images showing GB neck mass (black arrow) involving common hepatic duct (white arrow) as wall thickening. (c, d) Axial T₂W MR images of the same patient showing GB neck mass (arrowhead in d) & biliary dilatation (white arrows in c). (e, f) By lymph nodes. (e, f) Axial CT scans showing small GB mass (arrow head in f) with multiple peripancreatic nodes compressing the bile duct (white arrows).

Figure 10.

Metastasis: (a–c) Hematogeneous. (a) Liver. Axial CT image showing multiple hypodense lesions in liver. (b) Lung. Axial CT image in lung window showing multiple nodules in right lung (arrows). (c) Bone. Coronal CT image in bone window showing lytic lesions in multiple vertebral bodies (arrows). (d–f) Peritoneal. (d, e) Axial CT images showing soft tissue mass in the omentum (arrow in d) and solid-cystic lesions in both ovaries (arrows in e). (f) Coronal T₂W MR image showing mass in GB (asterisk) with nodular peritoneal thickening (arrows). GB, gallbladder.

Figure 11.

Complications. (a–b) Cholecystitis: Axial (a) and coronal (b) CT images showing GB wall thickening with pericholecystic fluid (arrows) in a patient with GB neck mass. (c–d) Tumor rupture: Axial CT images showing large GB mass (asterisk) with rupture and perihepatic fluid collection (arrow). (e–f) Cystic artery pseudoaneurysm. Axial venous phase (e) & sagittal arterial phase (f) CT images showing GB mass (black arrow) with calculus (white arrow) and pseudoaneurysm from cystic artery (arrow head). GB, gallbladder.

Figure 12.

Dual energy CT. (a, b) Iodine overlay CT maps of two patients with GB wall thickening (arrows) due to cholecystitis (a) and GBC (b). The degree of mucosal enhancement is higher in wall thickening due to malignancy (b) compared to that due to chronic inflammation (a). (c, d) Iodine overlay CT maps of two patients with intraluminal tumefactive sludge (arrowheads in c) and polypoid mass filling the lumen of GB (asterisk in d). Tumefactive sludge shows no evidence of iodine uptake compared to tumor, which shows diffuse and heterogeneous uptake. GB, gallbladder.

Figure 13.

Tumefactive sludge. (a) Ultrasonography shows echogenic mass-like area in the GB (arrow). (b, c) Axial CT images in arterial (b) and venous (c) phases showing hyperdense lesion in the lumen of GB (arrow). (d–f) Axial T2W (d), DWI (e) and ADC map (f) shows that the lesion is T2 hypointense with free diffusion. Hyperdensity on CT, T1 hyperintensity & free diffusion suggest tumefactive sludge. ADC, apparent diffusioncoefficient; GB, gallbladder.

Figure 14.

Assessing response to chemotherapy. (a, b) CT scans, before (a) and after (b) 6 cycles of chemotherapy shows reduction in the tumor size. (c, d) PET-CT images before (c) and after (d) chemotherapy also shows reduction in size and activity. PET-CT thus is better as it still shows residual activity. PET, positron emission tomography.

Figure 15.

Gallbladder adenomyomatosis. (a) Longitudinal ultrasound image of gallbladder shows an area of mural thickening containing multiple foci of comet tail artifacts (arrows), representing cholesterol crystals. (b–d) Axial T₂ weighted MRI image (b) of another patient shows smooth mural thickening (arrowheads) in the fundus of gallbladder with hypointense signal. Contrast enhanced T₁ weighted arterial (c) and portal venous (d) phase images show uniform mucosal enhancement in the region of mural thickening (block arrows). Features are suggestive of localized form of adenomyomatosis.

Figure 16.

Post-radiation changes. (a) Axial CT image showing low attenuation focal area with straight margins (arrowheads) corresponding to radiation portal suggestive of radiation induced liver injury. (b) Axial CT image of another patient with GBC, showing circumferential low density gastric wall thickening (arrows) and luminal narrowing predominantly in the gastric antrum and pyloric region suggestive of post radiation gastritis. GBC, gallbladder cancer.

Figure 17.

Limitation of CT in assessing response. CT scans (a, c) & PET-CT (b, & d), before and after chemotherapy respectively. CT scan shows persistent mass (arrow in c) suggesting residual disease, but PET-CT shows no residual activity (arrow in d). PET-CT thus assesses functional nature of the disease after treatment. PET, positron emission tomography.

Figure 18.

DWI for treatment response assessment: T₂W & DWI images – before (a, c) and after (b, d) three cycles of chemotherapy, shows reduction in the size of the lesion & also the diffusion restriction. ADC maps before (e) and after (f) first cycle of chemotherapy shows increase in ADC values from 1.14 (×10⁻³ mm² s⁻¹) to 1.39 (×10⁻³ mm² s⁻¹), suggesting response to chemotherapy. ADC, apparent diffusion coefficient; DWI, diffusion-weighted imaging.

Figure 19.

Biliary drainage: (a) External catheter drainage (arrow). (b, c) Internal-external catheter drainage, unilobar (arrow in b) & bilobar (arrows in c). (d) Internal drainage with bilobar stenting (arrows).

Figure 20.

Portal vein embolization. Right portal venogram, before (a) & portal venogram after (b) embolization with n-butyl cyanoacrylate (arrow). Glue cast is seen in the branches of right PV (arrow heads in b). Axial contrast enhanced MR images before (c) and 3 weeks after (d) portal vein embolization shows hypertrophy of left lateral segments (asterisk) and atrophy of embolized right lobe. PV, portal vein.