Hypercalcemia in Langerhans' cell granulomatosis with elevated 1,25 dihydroxyvitamin D (calcitriol) level

A 48-year-old woman presented with a history of premature menopause, polyuria, polydipsia, fever, and diffuse bony tenderness. Her evaluation revealed central diabetes insipidus, hypothalamic amenorrhea, an elevated free calcium on multiple occasions with an elevated 1,25 dihydroxyvitamin D level, and osteoporosis by densitometry. Skeletal series revealed multiple lytic lesions involving the long bones. The diagnosis of Langerhans' cell granulomatosis was made. She was treated with hormone replacement therapy, radiotherapy, and vinblastine, with a dramatic improvement in her pain and a near normalization of her free calcium. Whereas hypercalcemia has been described in several granulomatous disorders and is secondary to unregulated extrarenal production of 1,25 dihydroxyvitamin D, it is, however, extremely rare in Langerhans' cell granulomatosis. This is the first case report of Langerhans' cell granulomatosis with hypercalcemia and documented elevated increased 1,25 dihydroxyvitamin D level that responded to the treatment of her primary disease.