Background: A 48-year-old man with a recent diagnosis of multiple myeloma and rapidly progressive oliguric end-stage renal disease requiring hemodialysis, presented with a serum calcium concentration of 3.4 mmol/l (13.6 mg/dl).
Investigations: Serum laboratory analysis, electroencephalogram, MRI of the brain and bone marrow, and kidney biopsies.
Diagnosis: Hypercalcemia secondary to multiple myeloma.
Management: Short-term intravenous disodium pamidronate therapy (30 mg daily) and daily monitoring of serum calcium concentration.