Oncogenic osteomalacia diagnosed by blood pool scintigraphy
A 56-year-old male presented with progressive lower limb weakness and inability to walk with generalized body pains. Magnetic resonance imaging (MRI) reported lumbar canal stenosis. The patient gradually became wheel chair bound with severe body aches for more than 3 years. As his MRI brain was normal, tropical spastic paraparesis was suspected.\nThe patient later presented to our hospital, where he was thoroughly evaluated. Biochemically, serum alkaline phosphatase was raised in the presence of normal serum calcium, parathormone (PTH), reduced vitamin D3, and serum phosphorus. Urinary calcium excretion (24 h) was normal, but with hyperphosphaturia. X-ray pelvis suggested severe osteoporosis, while a whole body Tc 99m methylene diphosphonate (MDP) skeletal scintigraphy showed features of metabolic bone disease.\nBased on this, a diagnosis of hypophosphatemic osteomalacia was made and the patient was started on oral phosphate replacement. While all other causes of hypophosphaturia were ruled out, tumor induced osteomalacia had to be investigated.