A 35-year-old man presents with gross loosening of both his lower left premolar teeth. The gingiva around them looks swollen and is purple–brown in colour. A radiograph shows irregular bone destruction to the apices. Incisional biopsy shows multinucleated osteoclast-like giant cells in a haemorrhagic fibrous stroma.

1. Which investigations should now be performed?
   The serum calcium level should be measured and radiographs reviewed to exclude hyperparathyroidism.
   
2. If these prove negative, what treatment should be undertaken?
   The lesion should be treated by local removal with curettage.
   
3. Which other lesions in the jaws contain multinucleate giant cells of this type?
   Osteoclast-like giant cells are found in
   1. giant-cell granuloma
   2. brown tumour of hyperparathyroidism
   3. Pagetʼs disease of bone
   4. aneurysmal bone cyst
   5. some fibro-osseous lesions, particularly cherubism.