ADENOCARCINOMA OF PANCREAS WITH TROUSSEAU'S SYNDROME
Pancreatic carcinomas arise in the exocrine portion of the gland. Virtually all these cancers arise in the ductal epithelium. Pancreatic adenocarcinoma often grows silently, so that by the time it is diagnosed it will rarely be curable. The median survival time after diagnosis, regardless of therapy, is only a few months. Pancreatic cancer accounts for 5% of all cancer deaths in the United States. These tumors occur most often in the sixth, seventh, and eighth decades of life, although about 10% of patients are much younger. The incidence is increasing, but the causes are elusive. Smoking, diet, and chemical carcinogens have been implicated. There is a positive correlation between mortality from cancer of the pancreas and per capita consumption of fats and meat.
The lesions may arise anywhere in the pancreas: 60% are in the head, 15-20% in the body, and 5% in the tail of the pancreas. In 20% of cases, the tumor either is diffuse or has spread so widely that localization of the site of origin is impossible. Tumors of the head of the pancreas impinge upon the ampulla of Vater, common bile duct, and duodenum and thus cause obstructive biliary symptoms which may occur relatively early in the course. Tumors of the body and tail tend to grow silently and metastasize before diagnosis. These lesions are probably present for months to years before they produce symptoms due to their expansile growth. The major symptoms include weight loss, abdominal pain, back pain, anorexia, nausea, vomiting and generalized malaise, and weakness. Jaundice is present in about 90% of patients with carcinomas of the head and in 10 to 40% of those with cancer of the body or tail.
The symptomatic course of pancreatic cancer is typically brief and progressive. Despite the tendency of lesions of the head of the pancreas to obstruct the biliary system at a relatively earlier date, fewer than 15% of pancreatic tumors overall are resectable at the time of diagnosis. One year survival is less than 20%, and 5 year survival is only 3%.
Grossly, carcinomas of the head of the pancreas may be fairly small or up to 10 cm in diameter. The gray-white schirrous, homogenous tumor infiltrates and replaces the lobular architecture of a normal pancreas. These lesions have poorly defined, obviously infiltrative magins. Larger tumors usually extend beyond the pancreas to invade the duodenum and common bile duct; biliary obstruction may occur by compression or outright growth of tumor into the biliary space. Extension to peripancreatic and portohepatic nodes, with metastasis to the liver, is not uncommon.
The histologic appearance of pancreatic carcinoma is generally that of a poorly differentiated adenocarcinoma forming abortive tubular structures or cell clusters and exhibiting an aggressive, deeply infiltrative growth pattern. The malignant glands are atypical, irregular, small, and bizarre and are usually lined by anaplastic cuboidal to columnar epithelial cells. Well to moderately differentiated tumors are the exception. There may be areas of ductal dsyplasia and intraductal tumor growth. Dense stromal fibrosis accompanies tumor invasion, and there is often perineural invasion within and beyond the organ. This perineural invasion often accounts for intractable pain.
Migratory thrombophlebitis, known as Trousseau's syndrome, which occurs in about 10% of patients with pancreatic adenocarcinoma, is attributed to the elaboration of platelet-aggregating factors and procoagulants from the tumor or its necrotic products. Both venous and arterial thrombi can occur. Venous thrombi can embolize to the lungs. A large "saddle" pulmonary embolus may result in sudden severe dyspnea and demise of the patient. Smaller emboli, as in this case, may produce pulmonary infarctions with some dyspnea and chest pain.
Contributed by Edward C. Klatt MD