[Tumoral hypocalcemia].

Hypocalcemia is a rare and not well understood paraneoplasic manifestation. We report the clinical case of a patient with hypocalcemia due to extensive osteoblastic metastasis. The corrected serum calcium levels for albumin was 7.2 mg/dl. Calciuria was less than 10 mg/24 h. Magnesium, phosphate and 25-hydroxyvitamin D levels were normal. PTH and 1,25-dihydroxyvitamin D levels were increased. The pathogenesis of this disorder is possibly related to the massive calcium flow toward metastatic areas, that can not be compensated for by the activity of the PTH-vitamin D axis.