THE PREOPERATIVE diagnosis of carcinoma of the pancreas remains a challenge in spite of the many excellent studies made since De Costa's article in 1857. In this paper 90 cases are reviewed and compared with those in other studies1in the hope that earlier recognition of the disease may be accomplished. PATHOLOGIC FEATURES In 85 of our cases the diagnosis was confirmed by operation and usually corroborated by biopsy, and in some instances it was also confirmed at autopsy. For 5 patients not subjected to operation the diagnosis was confirmed at autopsy. In a few cases it is not absolutely certain whether the primary lesion was precisely pancreatic or ampullar, but in all involvement of pancreatic tissue was clear. The anatomic location of the lesion in this series is shown in table 1. As would be expected, the head of the pancreas was usually involved in patients with