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The “necklace appearance” of the mass was more clearly demonstrated on magnetic resonance imaging, representing bile in the Rokitansky-Aschoff sinuses. The gallbladder lumen was narrowed because of the hypertrophic mucosa and muscular wall. The bile was hyperintense on T1- and T2-weighted images. Diffuse adenomyomatosis of the gallbladder was indicated, but occult gallbladder cancer could not be excluded. A 9 × 6 × 4-cm pink gallbladder mass was resected. Narrowed lumen (7 × 1 × 0.7 cm) was apparent (Figure 2). Adenomyomatosis was diagnosed microscopically. There was no evidence of gallbladder cancer.
Photograph of the gross pathologic specimen obtained by cholecystectomy reveals hypertrophy of the muscular wall (*) and narrowing of the lumen (L).
Adenomyomatosis of the gallbladder is a relatively common disease that is found in 2% to 5% of specimens obtained at cholecystectomy.1 Pathologically, it is defined by epithelial proliferation and hypertrophy of the muscularis of the gallbladder, with outpouching of the mucosa into the thickened muscular layer (Rokitansky-Aschoff sinuses).1,2 The pathogenesis of this condition remains unknown. Nevertheless, gallbladder adenomyomatosis seems unlikely to be a congenital lesion because its incidence increases with age, with the majority of individuals with the disease in their 50s and 60s.3
Adenomyomatosis of the gallbladder has been defined as segmental, diffuse, and fundal in terms of morphology type. The segmental type in particular appears to be a predisposing factor for cholelithiasis.2 Clinical features of this condition are similar to those of gallstones and/or cholecystitis. This disorder is increasingly being recognized in asymptomatic cases and incidentally during imaging investigation.4 Ultrasonography is the most widely used method for evaluating suspected gallbladder diseases; however, recent studies suggest that magnetic resonance imaging may be the more accurate diagnostic tool for gallbladder adenomyomatosis.1,4
What is the relationship between gallbladder carcinoma and adenomyomatosis of the gallbladder? Adenomyomatosis is currently considered to carry no risk of malignant change. However, there has been reported to be a strong association between gallbladder cancer and segmental-type adenomyomatosis of the gallbladder.5 Furthermore, a well-differentiated gallbladder carcinoma with mucin production can have cystic components that may mimic adenomyomatosis.6 In this patient, in addition to the clinically persistent symptoms, the imaging findings led us to perform cholecystectomy because of the possibility of occult cancer and the risk of malignancy.
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Correspondence: Ray-Hwang Yuan, MD, PhD, Department of Surgery, National Taiwan University Hospital, No. 7, Chung-Shan South Road, Taipei 100, Taiwan (firstname.lastname@example.org).
Accepted for Publication: January 26, 2007.
Author Contributions:Study concept and design: Liu and Yuan. Acquisition of data: Liu, Yang, and Lee. Analysis and interpretation of data: Liu and Yuan. Drafting of the manuscript: Liu and Yuan. Critical revision of the manuscript for important intellectual content: Yang, Lee, and Yuan. Administrative, technical, and material support: Yang and Lee. Study supervision: Yuan.
Financial Disclosure: None reported.
Image of the Month—Diagnosis. Arch Surg. 2008;143(11):1130. doi:10.1001/archsurg.143.11.1130