Context: Patients with known or suspected pancreatic adenocarcinoma are typically evaluated with noninvasive imaging studies and endoscopic ultrasound. Rarely, patients require intraoperative evaluation with intraoperative ultrasound to identify mass lesions. Some patients have pancreatic adenocarcinomas that cannot be detected using any of these methods.
Case report: A-58-year old female presented with a distal common bile duct stricture seen on ERCP with negative brushings. Multiple endoscopic ultrasound and triple phase pancreatic protocol CT exams were negative for a mass lesion and revealed a normal pancreas. Intraoperative ultrasound of the pancreas was also felt to be normal. Intraoperative biopsy of the head of the pancreas revealed a small, moderately to poorly differentiated adenocarcinoma, not visible on any of her imaging studies.
Conclusion: Some pancreatic adenocarcinomas may defy detection using modern imaging modalities. This case illustrates how extensive imaging failed to detect a malignancy prior to surgery. Patients with a high clinical suspicion for malignancy but no visualized mass should undergo operative evaluation with definitive tissue sampling.