From the Guidelines
Adenomyomatosis of the gallbladder is a condition characterized by mural hyperplasia, which may be diffuse, focal, or segmental, with characteristic features including comet-tail artifact or twinkling artifact due to intramural cholesterol crystals, and Rokitansky-Aschoff sinuses appearing as intramural cysts. This condition is often discovered incidentally during imaging for other conditions, and most cases are asymptomatic. According to the Society of Radiologists in Ultrasound consensus conference recommendations 1, adenomyomatosis is defined by these specific imaging characteristics, which distinguish it from other gallbladder conditions such as gallstones or polyps.
Key Characteristics
- Mural hyperplasia, which may be diffuse, focal, or segmental
- Comet-tail artifact or twinkling artifact due to intramural cholesterol crystals
- Rokitansky-Aschoff sinuses appearing as intramural cysts
Management
If symptoms occur, such as right upper quadrant pain, treatment options may include pain management with NSAIDs or acetaminophen. For persistent or severe symptoms, surgical removal of the gallbladder may be recommended. Regular monitoring with ultrasound is advised for asymptomatic cases to ensure stability, as there is a potential risk of gallbladder cancer in diffuse forms of adenomyomatosis 1.
Risk Factors
Risk factors for adenomyomatosis include age, female gender, and possibly chronic inflammation. The condition develops when increased pressure inside the gallbladder causes the lining to herniate into the muscle layer, creating the characteristic sinuses.
Diagnosis
Diagnosis is typically made through imaging studies, such as ultrasound, which can reveal the characteristic features of adenomyomatosis, including the comet-tail artifact or twinkling artifact, and Rokitansky-Aschoff sinuses 1.
From the Research
Definition and Characteristics of Adenomyomatosis of the Gallbladder
- Adenomyomatosis of the gallbladder (GBA) is a hyperplastic disease affecting the wall of the gallbladder, characterized by thickening of the gallbladder wall 2.
- It is a benign acquired gallbladder disease that can mimic cancer on radiological findings, leading to a diagnostic dilemma 3.
- GBA is a degenerative and proliferative disease characterized by excessive epithelial proliferation associated with hypertrophy of muscularis propria, leading to outpouchings of mucosa into or beyond the muscle layer forming intramural diverticula recognized as Rokitansky-Aschoff sinuses (RAS) 4.
Types of Gallbladder Adenomyomatosis
- Three types of GBA are recognized: fundal, segmental, and diffuse type 4.
- In fundal GBA, there is focal thickening involving the GB fundus.
- In segmental GBA, there is circumferential overgrowth of the GB wall that leads to formation of compartments.
- In diffuse GBA, there is disseminated thickening and irregularity of the mucosa and muscularis.
Diagnosis of Gallbladder Adenomyomatosis
- Diagnosis of GBA is by imaging showing thickened gallbladder wall containing cysts 4.
- Characteristic features are "comet-tail" artefacts and "twinkling" artefacts on ultrasound (US), "pearl-necklace sign" on magnetic resonance imaging (MRI), and "rosary sign" on computed tomography (CT) 4, 5, 6.
- US is the imaging modality of choice for diagnosing GBA, and high-frequency probes and precise focal depth adjustment enable correct identification and characterization of GBA in the majority of cases 5.
Management of Gallbladder Adenomyomatosis
- Cholecystectomy should be offered for symptomatic GBA of any type 4.
- For asymptomatic GBA, cholecystectomy may be considered for segmental type for its increased risk of malignancy and for diffuse type for its difficult visualization of any coexisting malignancy 4.
- Asymptomatic fundal GBA can be safely observed with US, but the frequency and duration of monitoring remain unknown 4.
- In case of diagnostic doubt, cholecystectomy should always be offered to avoid overlooked malignancy 4.