Uncovering Hypercalcemia of Malignancy Following Parathyroidectomy for Hyperparathyroidism

Hypercalcemia is a common complication of malignancy, often attributed to elevated PTH-related protein levels mimicking the effects of PTH and promoting bone resorption. We present the case of a 67-year-old Hispanic female with a history of hypertension, type 2 diabetes mellitus, hyperlipidemia, and chronic kidney disease, who initially underwent parathyroidectomy for suspected primary hyperparathyroidism resulting from persistent hypercalcemia. Despite surgery, the patient continued to experience hypercalcemia and was subsequently diagnosed with diffuse large B-cell lymphoma with hypercalcemia as a rare but life-threatening complication. This case highlights the importance of considering malignancy as a potential cause of hypercalcemia, particularly in the context of hematologic malignancies such as diffuse large B-cell lymphoma. Prompt recognition and management are crucial to prevent severe complications associated with hypercalcemia. A multidisciplinary approach involving oncologists, endocrinologists, and supportive care teams is essential for effective management in such cases.