Brown's tumour is seen in:

Advanced primary hyperparathyroidism pathognomonic radiologic findings, which are best seen on x-rays of the hands and are characterized by subperiosteal resorption. The skull also may be affected and appears mottled with a loss of definition of the inner and outer coices. Brown or osteoclastic tumors and bone cysts also may be present. Ref: Schwaz's principle of surgery 9th edition, chapter 38.