What is the management and treatment of adenomyomatosis of the gallbladder?

Management and Treatment of Adenomyomatosis of the Gallbladder

For gallbladder adenomyomatosis (GA), management should be based on morphology, symptoms, and risk factors, with cholecystectomy recommended for symptomatic cases or those with high-risk features. 1

Diagnosis and Characterization

• Adenomyomatosis is characterized by gallbladder wall thickening containing small bile-filled cystic spaces called Rokitansky-Aschoff sinuses (RAS) 2
• Ultrasound (US) is the imaging modality of choice for diagnosing GA, with high-frequency probes enabling correct identification in most cases 2
• Three types of GA are recognized: fundal (focal thickening at fundus), segmental (circumferential wall overgrowth), and diffuse (disseminated thickening throughout) 1
• MRI should be reserved for cases unclear on US, with RAS appearing as the characteristic "pearl-necklace sign" 2, 1
• Contrast-enhanced ultrasound (CEUS) can help differentiate GA from other conditions when RAS cannot be clearly identified at baseline US 2

Management Algorithm

Symptomatic Adenomyomatosis

• Cholecystectomy is recommended for all symptomatic GA regardless of type 1
• Surgical risk related to cholecystectomy is minimal (2-8% morbidity) and most closely associated with surgical indication and underlying comorbidities 3
• The risk of bile duct injury during cholecystectomy is approximately 0.3-0.6% 3

Asymptomatic Adenomyomatosis

1. Segmental type:

   • Consider cholecystectomy due to increased risk of malignancy 1, 4
   • Studies have shown that 64% of adenomyomatosis-positive gallbladder cancers were of the segmental type 4

2. Diffuse type:

   • Consider cholecystectomy due to difficulty in visualizing any coexisting malignancy 1
   • No diffuse-type cases were found in a series of gallbladder cancers, suggesting lower malignant potential 4

3. Fundal type:

   • Can be safely observed with ultrasound follow-up 1
   • Represents 36% of adenomyomatosis-positive gallbladder cancers 4

Special Considerations

• If differentiation between tumefactive sludge and adenomyomatosis is challenging, short-interval follow-up US within 1-2 months with optimized technique is recommended 3
• CEUS or MRI should be considered if uncertainty persists after follow-up US 3
• CT has inferior diagnostic accuracy compared to CEUS or MRI for characterizing gallbladder lesions 3

Risk Factors for Malignancy

• Adenomyomatosis-positive gallbladder cancer is often diagnosed at advanced stages 4
• The segmental type has been associated with a higher risk of malignancy compared to other types 1, 4
• Chronic inflammation and lithiasis secondary to adenomyomatosis may lead to dysplastic changes and cancer 5

Follow-up Recommendations

• For asymptomatic fundal GA under observation, optimal frequency and duration of US follow-up remain undefined 1
• The Society of Radiologists in Ultrasound (SRU) consensus suggests that extended follow-up of gallbladder lesions is not productive, with a maximum of 3 years being sufficient to identify the vast majority of polyp-associated malignancies 3

Common Pitfalls

• Misdiagnosing adenomyomatosis as chronic cholecystitis or gallbladder cancer 6
• Overlooking pathognomonic signs of adenomyomatosis on ultrasound, such as "comet-tail" artifacts and "twinkling" artifacts 1
• Failing to recognize that preceding adenomyomatosis may prevent early detection of gallbladder cancer 4
• In cases of diagnostic doubt, cholecystectomy should be offered to avoid overlooking malignancy 1