title: Primary hyperparathyroidism presenting as anticonvulsant-induced osteomalacia.
abstract: A patient presented with the classic features of anticonvulsant-induced osteomalacia. Following discontinuance of diphenylhydantoin therapy and repletion with physiologic quantities of vitamin D, hypercalcemia and persistent biochemical hyperparathyroidism developed, and a parathyroid adenoma was removed. A history of nephrolithiasis and hypercalcemia preceding the institution of drug therapy allowed this patient's underlying parathyroid disease to be defined as primary hyperparathyroidism, which had been obscured by anticonvulsant therapy.
mesh_terms: D000236:Adenoma / Q000175:diagnosis; D000328:Adult; D000941:Antigens; D002118:Calcium / Q000097:blood; D000242:Cyclic AMP / Q000378:metabolism; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D006961:Hyperparathyroidism / Q000150:complications / Q000175:diagnosis* / Q000378:metabolism; D010018:Osteomalacia / Q000139:chemically induced* / Q000175:diagnosis; D010281:Parathyroid Hormone / Q000097:blood; D010282:Parathyroid Neoplasms / Q000175:diagnosis; D010672:Phenytoin / Q000009:adverse effects*; D014808:Vitamin D Deficiency / Q000150:complications
chemical_list: D000941:Antigens; D010281:Parathyroid Hormone; D010672:Phenytoin; D000242:Cyclic AMP; D002118:Calcium