[Bone pain, polydipsia, polyuria]

This 20 year old man suffered increasingly from multifocal bone- and back pain over the last 6 months. Painful weakness of the left leg with dysesthesia of the 4th and 5th toe, a weight loss of 15 kg and polydipsia and pollakiuria had developed. The clinical workup disclosed hard tumors in the right mandible and tibia, a waddling gait with bilateral sign of Trendelenburg, reduced muscular force in the left leg with missing achilles tendon reflex and a loss of sensibility in the distal S1 segment, epigastric tenderness on pressure and hypertension with a value of 160/100 mmHg. X-rays revealed multiple cystic bone lesions at all sites. Hypercalcemia and massively elevated parathyroid hormone were measured. Since the parathyroids were enlarged on sonography, primary hyperthyroidism with fibrosing osteitis v. Recklinghausen was diagnosed.