Endocrine Abstracts

Brown tumours are benign osteolytic lesions of bone caused by high levels of serum parathyroid hormone (PTH). They are now rarely seen as a feature of primary hyperparathyroidism. We report two cases of brown tumour in adolescent girls caused by secondary hyperparathyroidism due to severe vitamin D and dietary calcium deficiency.

Case 1: 14.5-year-old South Asian girl referred with a 1 year history of right hip pain. She had presented to the orthopaedic team with a low trauma fracture of her right fibula. X-ray and MRI scan of the hip which showed a brown tumour in the foot of her right acetabulum.

Case 2: 13.6 year old South Asian girl referred by the orthopaedic team with a 2 year history of gradually worsening pain of the right knee but no history of trauma. X-rays and MRI scans showed a Looser’s zone (insufficiency fracture) in the right distal femur and a 2.1 cm brown tumour in the right proximal fibula.

Both girls had low calcium intake and presented in Spring

Investigations: Both patients were managed with daily oral supplementation vitamin D2 9,000 units and 500mg of calcium once daily.

Conclusion: Brown tumours, though rare, can be a manifestation of vitamin D deficiency. These cases highlight that dark-skinned adolescents are at risk of vitamin D deficiency and require vitamin D supplementation during the English winter and spring. Currently there are no national recommendations for vitamin D supplementation in this group.