title: Spontaneous return of normocalcemia. Association with long-term hypoparathyroidism.
abstract: A 58-year-old man was admitted to the hospital with the superior vena cava (SVC) syndrome. The patient had a 13-year history of hypocalcemia resulting from surgically induced hypoparathyroidism, which he controlled with calcium lactate. Nine months before admission, he discontinued his daily therapy and still remained in a normocalcemic state. After he had the SVC syndrome, a small-cell tumor of the lung was found. His serum calcium level decreased after radiation of the tumor mass, suggesting that the tumor may have been secreting a substance producing the normocalcemia. A substance was extracted from the tumor that reacted immunologically like parathyroid hormone.
mesh_terms: D002118:Calcium / Q000097:blood*; D002277:Carcinoma / Q000032:analysis / Q000378:metabolism*; D006729:Hormones, Ectopic / Q000378:metabolism*; D006801:Humans; D007011:Hypoparathyroidism / Q000209:etiology*; D008175:Lung Neoplasms / Q000032:analysis / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D010281:Parathyroid Hormone / Q000032:analysis; D011183:Postoperative Complications; D012075:Remission, Spontaneous; D013965:Thyroidectomy; D013997:Time Factors
chemical_list: D006729:Hormones, Ectopic; D010281:Parathyroid Hormone; D002118:Calcium