[Primary hyperparathyroidism in a patient with systemic lupus erythematosus]

Primary hyperparathyroidism (PHP) is a metabolic illness that results from autonomous secretion of parathyroid hormone and is one of the most common causes of hypercalcemia. We present the case of a 47-year-old female with a previous diagnosis of systemic lupus erythematosus (SLE) in whom clinical (diffuse bone pain, emotional lability, jaw tumor) and laboratory features (calcium= 13.5 mg/dL, phosphate= 1.8 mg/dL, alkaline phosphatase= 3028 U/L, PTH intact= 1472 pg/dL) prompted the diagnosis of PHP secondary to parathyroid adenoma as demonstrated by the anatomopathology. After treatment with calcitonin spray 400 UI per day, IV pamidronate 90 mg/week, and subtotal parathyroidectomy, the patient status improved with normal laboratory tests. This is the second report to describe the coexistence of these two disorders in a single patient. Although the pathophysiology of the association of PHP and SLE is not known, the recognition of this association has a practical implication since the therapeutical strategy is completely different.