Preoperative diagnosis and staging of gallbladder carcinoma by EUS

Background. EUS has recently been shown to be efficacious for the preoperative assessment of depth of invasion of gallbladder carcinoma. This study assessed the value of EUS for determining T stage (international Union Against Cancer). Methods: Preoperative EUS findings in 41 patients with gallbladder carcinoma were analyzed retrospectively. EUS images were classified according to the shape of the tumor and the adjacent gallbladder wall structure as follows: type A, pedunculated mass with preserved adjacent wall structures; type B, sessile and/or broad-based mass with a preserved outer hyperechoic layer of the gallbladder wall; type C, sessile and/or broad-based mass with a narrowed outer hyperechoic layer; type D, sessile and/or broad-based mass with a disrupted outer hyperechoic layer. EUS and histopathologic findings were compared, including the depth of invasion of the tumor in the resection specimen. Results: The 4 categories of EUS images of gallbladder carcinoma correlated with the histologic depth of invasion and T stage. Accuracies for the EUS classification as type A corresponding to pTis, type B to pT1, type C to pT2, and type D to pT3-4 were, respectively, 100%, 75.6%, 85.3%, and 92.7%. Conclusions: Preoperative EUS imaging accurately depicts T stage of gallbladder carcinoma and allows for effective therapeutic decision making.