From the Guidelines
Adenomatosis of the gallbladder, also known as adenomatous polyps of the gallbladder, refers to a condition where there are multiple adenomas (benign tumors) in the gallbladder wall, with a significant risk of malignant transformation, particularly for polyps larger than 10 mm, as evidenced by a 2022 study published in Radiology 1.
Definition and Characteristics
Adenomatosis of the gallbladder is characterized by the presence of these adenomatous polyps, which are neoplastic in nature and have the potential to progress to gallbladder cancer. According to the 2019 WHO Classification of Tumours, fifth edition, Digestive System Tumours, intracholecystic papillary neoplasms (ICPNs) are defined as mass-forming, noninvasive epithelial neoplasms of 10 mm or more arising in the mucosa and projecting into the lumen of the gallbladder 1.
Risk of Malignancy
The risk of malignancy in adenomatous polyps of the gallbladder increases with the size of the polyps. A 2020 study found that polyps smaller than 6 mm had a 0% rate of malignancy, while polyps larger than 10 mm had a significantly higher risk, estimated at 0.4% in a 20-year population study 1.
Management
Surgical consultation is recommended for polyps of 15 mm or greater, and for polyps measuring 10-14 mm, the decision for surgical consultation may be made depending on patient factors or evidence of growth at follow-up imaging, as per the SRU consensus conference recommendations 1.
Treatment
The definitive treatment for adenomatosis of the gallbladder is surgical removal of the gallbladder (cholecystectomy), preferably laparoscopic if feasible. After diagnosis, surgery should be scheduled promptly, though it's not typically considered an emergency unless complications are present. No medication can effectively treat the underlying condition, though symptomatic relief may be provided with pain medications like acetaminophen or NSAIDs until surgery.
Follow-up
Following cholecystectomy, patients should have regular follow-up to ensure complete resolution, though recurrence is not typically a concern after complete removal of the gallbladder.
Key Points
- Adenomatosis of the gallbladder is a rare condition with a risk of malignant transformation.
- Polyp size is a significant factor in determining the risk of malignancy.
- Surgical removal of the gallbladder is the definitive treatment.
- Regular follow-up is necessary after surgery to ensure complete resolution.
From the Research
Definition and Characteristics of Adenomatosis of the Gallbladder
- Adenomatosis of the gallbladder, also known as adenomyomatosis, is a benign acquired gallbladder disease characterized by excessive epithelial proliferation associated with hypertrophy of muscularis propria 2.
- It leads to outpouchings of mucosa into or beyond the muscle layer, forming intramural diverticula recognized as Rokitansky-Aschoff sinuses (RAS) 2.
- There are three types of adenomyomatosis: fundal, segmental, and diffuse type, each with distinct characteristics 2.
Diagnosis and Management
- Diagnosis of adenomatosis of the gallbladder is typically made through imaging techniques such as ultrasound, magnetic resonance imaging (MRI), and computed tomography (CT) 3, 2.
- Characteristic features on imaging include "comet-tail" artefacts and "twinkling" artefacts on US, "pearl-necklace sign" on MRI, and "rosary sign" on CT 2.
- Management of adenomatosis of the gallbladder depends on the type and symptoms, with cholecystectomy recommended for symptomatic cases or those with a high risk of malignancy 3, 4, 2.
- Asymptomatic cases may be monitored with ultrasound, especially for fundal type adenomyomatosis 2.
Differential Diagnosis from Gallbladder Malignancy
- Adenomatosis of the gallbladder can be difficult to differentiate from gallbladder malignancy due to overlapping features 5.
- A combination of endoscopic techniques, such as endoscopic retrograde cholangio-pancreatography, intraductal ultrasound, and SpyGlass, may help in the differential diagnosis 5.
- Cholecystectomy is recommended in cases where the diagnosis is doubtful to avoid overlooked malignancy 3, 2.
Risk of Malignancy
- Adenomatosis of the gallbladder is generally considered a benign condition, but there is a potential risk of malignancy, particularly with segmental and diffuse types 4, 2.
- The risk of malignancy depends on various factors, including the size and type of adenomyomatosis, as well as the presence of risk factors such as age and family history of gallbladder carcinoma 6.