A female of 53 and male of 35 complained of myasthenia and pain in the
bones. Biochemically, they had severe hypophosphatemia secondary to a
sharp decline in tubular reabsorption of phosphates. X-ray showed tum
or of bone tissue. The patients were diagnosed to have oncogenic osteo
malacia. Literature data on pathogenesis, clinical features and treatm
ent of this rare disease are reviewed.