Clinicopathologic analysis of endoscopic ultrasonograms in pancreatic mass lesions.

Endoscopic ultrasonography (EUS) was performed in 40 patients with pancreatic masses who subsequently underwent surgical resection, and we compared the ultrasonograms with the histopathologic findings. Ductal adenocarcinoma: The cephalad margin between the tumor and pancreatic tissue was distinct, while the caudal margin was blurred because the severe fibrosis accompanying secondary pancreatitis, and the contour of the tumor was irregular. The internal echo pattern was hypoechoic, with an uneven central echogenic portion corresponding to irregularly arranged carcinomatous canaliculi or coagulation necrosis. Benign islet cell tumor: Both the cephalad and caudal margins were distinct, the contour was smooth and the internal echo pattern was hypoechoic, with a homogeneous central echogenic portion corresponding to regularly arranged alveoli. Pseudotumorous pancreatitis: The caudal margin was indistinct, the contour was smooth, and the internal echo pattern was homogeneously hypoechoic, with deep attenuation caused by dense fibrosis. On the basis of these results, it is believed that EUS with its high resolution is useful in the differential diagnosis of pancreatic mass lesions.