Deftos L J, Burton D W, Baird S M, Terkeltaub R A
Department of Medicine, University of California, San Diego, USA.
Arthritis Rheum. 1996 Dec;39(12):2066-9. doi: 10.1002/art.1780391217.
Hypercalcemia is commonly caused by the increased production of parathyroid hormone-related protein (PTHrP) by a malignancy. In fact, the demonstration of increased PTHrP production in a patient with hypercalcemia is virtually pathognomonic of malignancy. We studied a patient with systemic lupus erythematosus (SLE), generalized lymphadenopathy, and hypercalcemia. Immunohistology of 2 biopsied lymph nodes revealed the abundant expression of PTHrP and the absence of malignant transformation. Although apparently rare, PTHrP production by non-malignant lymphoid tissue may occur in SLE and should be considered in the differential diagnosis of hypercalcemia.
