Tertiary hyperparathyroidism is-
Davidson states "In very small proportion of cases of secondary hyperparathyroidism continuous stimulation of the parathyroid may result in adenoma formation and autonomous PTH secretion. This is known as tertiary ​hyperparathyroidism".
High PO
4
 level with metastasis
Secondary hyperparathyroidism with CRF
Primary hyperparathyroidism with low Cam' levels
Secondary hyperparathyroidism with chief cell adenoma