Pancreatic islet cell carcinoma with hypercalcemia. Primary hyperparathyroidism or humoral hypercalcemia of malignancy

Abstract

A 60-year-old woman presented with hypercalcemla and was found to have metastatic pancreatic Islet cell carcinoma. Although clinical features were very suggestive of hyperparathyroldism, her parathyroid hormone levels were not elevated and no abnormal parathyroid tissue was detected by thallium-technetium or computed tomographic scanning techniques. Her hypercalcemia appeared to be due to a humoral factor-distinct from parathyrold hormone-that mimics the action of parathyroid hormone almost exactly. The various tools that may be used to differentiate primary hyperparathyroldism from the humoral hypercalcemia of malignancy are reviewed.