Hungry bone syndrome and bone scintigraphy in a post parathyroidectomy patient

Learning Objectives 1. Understand the pathophysiology of hungry bone syndrome. 2. Illustrate the appearance of hungry bone syndrome on bone scintigraphy. 3. Discuss the biochemical changes in hungry bone syndrome.

A 42-year-old man with a history of multiple renal stones presented with right leg pain. Plain radiographs showed a lytic lesion at the proximal tibia. Bone scintigraphy demonstrated a metabolic superscan with mildly increased uptake at the tibial lesion. Sestamibi scanning showed evidence of a large parathyroid adenoma. Following parathyroidectomy, the patient experienced hypocalcemia and worsening of his leg pain. Repeat bone scintigraphy showed an increase in the intensity of uptake at the tibial lesion and the appearance of new lesions in keeping with brown tumors. This flare-up phenomenon is consistent with hungry bone syndrome which occurs after an abrupt decrease in parathyroid hormone following parathyroidectomy