Hypercalcemia and elevated serum 1,25-dihydroxyvitamin D3 in a patient with Hodgkin's lymphoma.

A 74-year-old woman was hospitalized because of decreased appetite, fatigue, and weight loss. The laboratory examination revealed hypercalcemia, a slightly increased serum creatinine level, and a markedly elevated serum level of 1,25-dihydroxyvitamin D3. The most important finding the physical examination revealed was enlarged inguinal lymph nodes. A biopsy disclosed lymphocyte-depleted Hodgkin's disease. After steroids, but not after calcitonin, both the elevated calcitriol concentration and serum calcium normalized. In spite of intensive chemotherapy, a further episode with hypercalcemia occurred and increased 1,25-dihydroxyvitamin D3 serum levels were observed. According to the available evidence it seems probable that the humoral hypercalcemia in this patient resulted from production of 1,25-dihydroxyvitamin D3 in the tumor.