Adenomyomatosis

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Ultrasound of gallbladder adenomyosis

Adenomyomatosis is a benign condition of the gallbladder characterized by the hyperplastic growth of the mucosa, thickening of the muscular wall, and formation of Rokitansky-Aschoff sinuses, which are deep invaginations of the epithelium into the muscular layer. This condition is considered a form of hyperplastic cholecystoses, which also includes cholesterolosis (often referred to as strawberry gallbladder). Adenomyomatosis can occur throughout the gallbladder (diffuse form) or be localized to a segment (segmental) or even to a particular area (focal).

Etiology and Pathogenesis

The exact cause of adenomyomatosis is not well understood, but it is thought to result from an abnormal response of the gallbladder wall to chronic irritation or inflammation. This could be due to gallstones, biliary sludge, or other factors that increase the risk of gallbladder disease. The condition leads to an overgrowth of the gallbladder epithelium and muscle layer, with the formation of Rokitansky-Aschoff sinuses.

Clinical Presentation

Most individuals with adenomyomatosis are asymptomatic, and the condition is often discovered incidentally during imaging studies for unrelated reasons. When symptoms do occur, they may mimic those of gallstones or chronic cholecystitis, including right upper quadrant abdominal pain, nausea, and vomiting.

Diagnosis

Adenomyomatosis is primarily diagnosed through imaging techniques. Ultrasound is often the first modality used, where it can show characteristic findings such as small cystic spaces within the gallbladder wall, which represent the Rokitansky-Aschoff sinuses. Other imaging modalities that can help in the diagnosis include computed tomography (CT) and magnetic resonance imaging (MRI), with MR cholangiopancreatography (MRCP) being particularly useful in delineating the anatomy of the biliary tree and the detailed structure of the gallbladder wall.

Treatment

In asymptomatic patients, no treatment is generally necessary. For those who experience symptoms, cholecystectomy, the surgical removal of the gallbladder, is the definitive treatment. This procedure is typically performed laparoscopically and has a good prognosis.

Prognosis

The prognosis for individuals with adenomyomatosis is excellent, especially in cases where the condition is asymptomatic or when symptomatic cases are treated with cholecystectomy. There is no known association between adenomyomatosis and gallbladder cancer.