Hypercalcemia in squamous cell carcinoma of the renal pelvis? Parathyroid or paraendocrine in origin.

Hypercalcemia associated with metastatic cancer may be due to osteolytic invasion or paraendocrine effects of the neoplasm. A patient with refractory hypercalcemia of long duration underwent cervical parathyroid exploration; three glands were found, but hypercalcemia persisted. After localization studies, a fourth gland was uncovered from the mediastinum. Hypercalcemia persisted, and at operation for kidney stones, squamous cell carcinoma of the renal pelvis was discovered, which progressed to cause the patient's death in hypercalcemia.