Definition
Highly vascular lytic lesions of the skeleton seen in both primary and secondary hyperparathyroidism
Encountered as differential diagnosis of giant cell tumour.
Epidemiology
Most commonly seen with secondary hyperparathyroidism secondary to renal disease. May affect any age.
Site
Can affect any part of the skeleton.
Pathology
Grossly: brown friable material resulting from accumulation of haemosiderin within areas of haemorrhage.
Microscopically: giant cells aggregate around areas of haemorrhage, in a background of granulation tissue.
Biochemistry
Elevated calcium
Decreased phosphate
Elevated parathyroid hormone
Radiology
Lesions may be single or multiple, and are often cortical in location.
Typically lytic
Treatment
If the hyperparathyroidism can be corrected the lesions regress.
Can be surgically excised and bone grafted.