Spinal tumour due to primary hyperparathyroidism causing sciatica: case report.

We report a unilateral intraspinal cyst-like lesion adjacent to the lamina and facet joint at the L4-L5 level producing sciatica. Histological examination revealed multinucleate giant cells suggesting a brown tumour. Further studies disclosed primary hyperparathyroidism, whose first manifestation was the lumbar nerve root compression. Previous cases of compression of neural structures by spinal brown tumours are reviewed and a radiological differential diagnosis is presented.