Prostate cancer-induced oncogenic hypophosphatemic osteomalacia.

A 65-year-old male with prostate carcinoma showed mild hypocalcemia of 7.9 mg/dl, marked hypophosphatemia of 1.7 mg/dl, hyperphosphaturia (tubular reabsorption of phosphorus 43% and tubular threshold for phosphorus of 0.6 mg/dl), low serum 1,25 (OH)2D level of less than 5 pg/ml and osteomalacia indicated by a marked increase of relative osteoid volume and fractional formation rate in the undecalcified section. Oncogenic osteomalacia due to prostatic carcinoma with suppression of 1,25 (OH)2D production and phosphaturia was suggested.