The site of disease making the patient unresectable was confirmed by biopsy in each case. Thus laparoscopy with ultrasound was the best method to select patients for curative surgery. Nonpalpable tumors are most commonly in the pancreatic head. Others have recommended blind distal pancreatectomy for individuals with insulinoma in whom no tumor can be identified. However, our data suggest that this procedure is contraindicated as these occult tumors are usually within the pancreatic head.
Recent series suggest that previously missed gastrinomas are commonly in the duodenum.
IOUS is not able to identify these tumors, but other methods can. IOUS did not image a single tumor that was not palpable. In conclusion, laparoscopy with ultrasound is useful for selecting patients with pancreatic cancer for curative surgery. Ultrasound is critical for operative identification of insulinomas especially in the pancreatic head, and duodenotomy can identify duodenal wall gastrinomas that are missed by other methods. Glucagonoma, a rare neuroendocrine pancreatic tumour, is frequently malignant and often accompanied by hepatic metastases.