Pancreatic Islet Tumors

PANCREATIC ISLET TUMORS

The pancreas contains the islets (islands) of Langerhans, small nests of cells that secrete directly into the bloodstream and there-fore are part of the endocrine system. The hormone insulin is essential for the metabolism of glucose. Diabetes mellitus  is the result of deficient secretion of insulin.

At least two types of tumors of the pancreatic islet cells are known: those that secrete insulin (insulinoma) and those in which insulin secretion is not increased (“nonfunctioning” islet cell cancer). Insulinomas produce hypersecretion of insulin and cause an excessive rate of glucose metabolism. The resulting hypo-glycemia may produce symptoms of weakness, mental confusion, and seizures. These symptoms may be relieved almost immedi-ately by oral or intravenous administration of glucose. The 5-hour glucose tolerance test is helpful in diagnosing insulinoma and in distinguishing it from other causes of hypoglycemia.

Surgical Management

When a tumor of the islet cells has been diagnosed, surgical treat-ment with removal of the tumor usually is recommended. The tumors may be benign adenomas or they may be malignant. Complete removal usually results in almost immediate relief of symptoms. In some patients, symptoms may be produced by simple hypertrophy of this tissue rather than a tumor of the islet cells. In such cases, a partial pancreatectomy (removal of the tail and part of the body of the pancreas) is performed.

Nursing Management

In preparing the patient for surgery, the nurse must be alert for symptoms of hypoglycemia and be ready to administer glucose as prescribed if symptoms occur. Postoperatively, the nursing man-agement is the same as that after other upper abdominal surgical procedures, with special emphasis on monitoring serum glucose levels. Patient teaching is determined by the extent of surgery and the alterations in pancreatic function that result.