• Pseudohyperparathyroidism encompasses both ectopic hyperparathyroidism and the more commonly encountered nonparathyroid humoral hypercalcemia of malignancy—metastatic breast cancer being the classic example. Benign breast disease is a rare cause of hypercalcemia. We recently managed a patient with gigantic mammary hypertrophy that occurred during pregnancy who concomitantly manifested marked nonparathyroid hypercalcemia. This report strongly suggests that a causal relationship exists between benign breast disease and hypercalcemia.
(Arch Surg 1988;123:80-82)