Hypophosphatemic osteomalacia: an unusual clinical presentation of multiple myeloma

M. Reyskens, K. Sleurs, L. Veressen, M. Janssen, J. van den Berg, P. Geusens*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review


An unusual case of a 75-year-old man is presented who had multiple stress fractures due to adult onset hypophosphatemic osteomalacia, which was the result of Fanconi syndrome, with light chain cast proximal tubulopathy due to multiple myeloma. A 75-year-old man presented with diffuse pain and muscle weakness. He had multiple stress fractures, low serum phosphate, decreased renal tubular reabsorption of phosphate, and normal PTH and FGF23, indicating adult onset hypophosphatemic osteomalacia. Phosphate supplements with calcitriol resulted in clinical recovery and healing of stress fractures. Because of proteinuria, a renal biopsy was performed that revealed Fanconi syndrome with light chain cast proximal tubulopathy and light kappa chains were found in serum and urine. A bone biopsy confirmed the diagnosis of multiple myeloma, and treatment with chemotherapy resulted in cytological and clinical recovery.
Original languageEnglish
Pages (from-to)2039-2042
JournalOsteoporosis International
Issue number7
Early online date24 Apr 2015
Publication statusPublished - 24 Apr 2015

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