Atypical exocrine and endocrine pancreatic tumors (anaplastic, small cell, and giant cell types): CT and pathologic features in 14 patients

Background: Our purpose was to review a series of 14 patients with atypical exocrine and endocrine pancreatic tumors to derive characteristic computed tomographic and pathologic features that might allow better diagnosis, categorization, and management of these patients. Methods: Medical records from several university medical centers were reviewed retrospectively. Results: We identified three separate types of pancreatic tumors that had substantially different morphologic and prognostic features. Among these rare tumors, anaplastic carcinoma was the most common (nine of 14 cases), and these tumors were large, partly necrotic, locally invasive, and invariably metastatic (lymph nodes and/or liver) at the time of diagnosis. Three patients with poorly differ entiated (small cell) carcinoma had a confluent pancreatic mass and lymphadenopathy but no ductal obstruction, closely resembling lymphoma or metastatic disease. Two patients with giant cell (osteoclastlike) carcinoma had a large, encapsulated multicystic tumor with hemorrhage, and these tumors were resectable for cure. Conclusion: Although a specific diagnosis may not be possible in some cases, we believe that knowledge of certain pathologic and computed tomographic features should lead to optimal diagnosis, therapy, and prognosis.