Tumor-associated Hypercalcemia in a patient with Paget's disease.

Paget's disease of the bone, which is characterized by a focal region of highly exaggerated bone remodeling, is very rare in Asia. Most patients with Paget's disease are asymptomatic; they are normocalcemic and show elevated alkaline phosphatase levels. Hypercalcemia in patients with Paget's disease has rarely been reported. We report one Chinese patient with Paget's disease involving the maxilla bone with an initial presentation of facial cellulitis. Asymptomatic hypercalcemia with a low-normal intact parathyroid hormone level developed 9 years later. After clodronate treatment, the level of alkaline phosphatase normalized, but the hypercalcemia did not respond adequately. After analysis of tumor markers and imaging studies, a clinical diagnosis of pancreatic adenocarcinoma with multiple hepatic and lung metastases with pleural effusion was made. We suggest that malignancy-associated hypercalcemia should be considered as one of the causes of hypercalcemia in patients with Paget's disease.