Leiomyoblastoma associated with intractable hypercalcemia and elevated 1,25-dihydroxycholecalciferol levels. Treatment by hepatic enzyme induction.
A 42-year-old woman, with a previously resected jejunal leiomyoblastoma, was first seen with liver metastases 31/2 years after the tumor resection. Intractable malignant hypercalcemia appeared eight months later, together with renal insufficiency. No osteolytic lesions were detected. Levels of parathyroid hormone, cyclic adenosine monophosphate, and 1,25-dihydroxycholecalciferol (1,25[OH]2D) were not useful in distinguishing between the hypercalcemia of malignancy and concurrent hyperparathyroidism. Despite renal insufficiency, hypercalcemia, and subtotal parathyroidectomy, the 1,25(OH)2D levels remained elevated, consistent with the speculation that a tumor product stimulated 1-alpha-hydroxylation of 25-hydroxycholecalciferol. Phenytoin and phenobarbital (enzyme induction therapy), in combination with phosphorus and glucocorticoids, appeared to be useful in controlling the hypercalcemia.
D000328:Adult; D002117:Calcitriol / Q000097:blood*; D004790:Enzyme Induction / Q000187:drug effects; D005260:Female; D006801:Humans; D006934:Hypercalcemia / Q000188:drug therapy / Q000201:enzymology / Q000209:etiology*; D007889:Leiomyoma / Q000150:complications / Q000188:drug therapy; D008099:Liver / Q000201:enzymology*; D008113:Liver Neoplasms / Q000150:complications / Q000188:drug therapy / Q000556:secondary; D010634:Phenobarbital / Q000627:therapeutic use; D010672:Phenytoin / Q000627:therapeutic use
D010672:Phenytoin; D002117:Calcitriol; D010634:Phenobarbital