Elevations in circulating 1,25-dihydroxyvitamin D in three patients with lymphoma-associated hypercalcemia.
Three patients with hypercalcemia associated with malignant lymphoma and elevations in plasma 1,25-dihydroxyvitamin D [1,25-(OH)2D] are described. In addition to the elevation of circulating 1,25-(OH)2D, these three patients were characterized by suppressed immunoreactive PTH levels and urinary cAMP excretion, elevated fasting urinary excretion of calcium, and absence of adenylate cyclase-stimulating activity in the tumor extracts. Bone marrow biopsy and skeletal radionuclide scans were negative for lymphoma in two patients. Surgical excision of a solitary splenic lymphoma in one patient and medical therapy in another patient resulted in rapid normalization of the serum calcium and plasma 1,25-(OH)2D levels. These findings confirm an earlier observation that elevated plasma levels of 1,25-(OH)2D may occur in certain patients with lymphoma and suggest that this vitamin D metabolite may act as a humoral or systemic mediator of hypercalcemia. Proof that this is the case and identification of the source of 1,25-(OH)2D production will require further study.
D000368:Aged; D001402:B-Lymphocytes; D001853:Bone Marrow / Q000473:pathology; D002117:Calcitriol / Q000097:blood*; D003907:Dexamethasone / Q000627:therapeutic use; D006689:Hodgkin Disease / Q000097:blood / Q000150:complications; D006801:Humans; D006934:Hypercalcemia / Q000097:blood* / Q000209:etiology / Q000628:therapy; D008223:Lymphoma / Q000097:blood* / Q000150:complications / Q000601:surgery; D008297:Male; D008875:Middle Aged; D010257:Paraneoplastic Syndromes / Q000097:blood* / Q000628:therapy; D013160:Splenic Neoplasms / Q000097:blood / Q000150:complications / Q000601:surgery; D013601:T-Lymphocytes
D003907:Dexamethasone; D002117:Calcitriol