| Discussion: |
Pancreatic cancer is the fourth most common cancer in men and the fifth most common in women in the U.S. It occurs nearly twice as often in men as women, but rarely develops before
age 50. It is two to three times more common in heavy smokers than in non-smokers. People who have chronic pancreatitis are at a higher risk of developing pancreatic cancer.
Pancreatic cancer usually causes no symptoms until the tumor is large. At that point, the cancer has usually spread to nearby lymph nodes, the liver or the lungs. The first symptoms are usually abdominal pain and weight loss. About 80% of pancreatic cancers occur in the head of the pancreas. Jaundice occurs when the bile duct becomes obstructed. Other symptoms include mid back pain, nausea and diarrhea, general weakness, itchy skin,light colored bowel movements and slow digestion of food. The liver and gallbladder may be swollen.
The most common pancreatic malignant lesion is ductal adenocarcinoma. Few patients with this tumor are surgical candidates at presentation because of vascular encasement or metastatic disease. Patients with small tumors (less than 2cm) that have no vascular invasion or lymph node metastasis have the best prognosis. The 5 year survival rate after pancreatoduodenectomy is between 18% and 33%.
Intraoperative sonography can be used to detect and determine the extent of a small,nonpalpable pancreatic mass. Pancreatic ductal adenocarcinoma is usually a hypoechoic,solid mass with irregular margins. It frequently obstructs the pancreatic duct and common bile duct and causes ductal dilation up to the level of the mass. IOS can also be used to detect abnormal regional lymph nodes, vascular encasement by neoplasm, and liver metastatic lesions.Demonstrating occult liver metastatic lesions with IOS can prevent an unnecessary attempt at surgical resection.