An Exciting Case of Acute on Chronic Hypercalcemia in the Setting of Chronic Primary Hyperparathyroidism: A Case Report and Diagnostic Approach.

Acute worsening of hypercalcemia in patients with chronic primary hyperparathyroidism can be challenging, and availability bias may mislead physicians to diagnose worsening primary hyperparathyroidism, especially if the parathyroid hormone is also trending higher. We report a case of stage-IV non-Hodgkin's lymphoma which presented as acute worsening of hypercalcemia in a patient with chronic primary hyperparathyroidism.