Radiologic diagnosis and staging of pancreatic ductal adenocarcinoma.

IBD CT is the single best modality for diagnosis and staging of patients with suspected pancreatic carcinoma. While carefully performed real-time US is an excellent technique for determining the level and etiology of bile duct obstruction, it is of more limited value for diagnosis of tumors in the body and tail of the gland, and is less accurate than IBD CT for assessment of tumor resectability. Thus, most patients require IBD CT for accurate, nonoperative staging. ERCP and angiography continue to be useful adjunctive procedures for evaluation of patients with suspected pancreatic carcinoma, particularly for evaluation of equivocal CT or US findings. An isolated pancreatic mass, that is, a mass with no ancillary CT or US findings of carcinoma (local extension, distant metastases), is a non-specific finding and requires further evaluation with either ERCP or angiography, and perhaps most importantly, with FNAB. Other neoplasms may mimic pancreatic ductal carcinoma, particularly islet cell carcinoma and lymphoma. Pancreatitis also can result in a focal pancreatic mass, simulating a neoplasm. These diseases usually respond to therapy and thus it is essential to confirm the radiologic diagnosis of pancreatic carcinoma with biopsy, particularly if surgery is not planned or if chemoradiation therapy is anticipated.