Table 1.

Main clinical characteristics of familial hereditary forms of PHPT.

Syndrome	Mean age of onset	Parathyroid pathology	Clinical treatment
MEN1	20–25 years	Multiglandular hyperplasia and/or adenoma	Subtotal parathyroidectomy of hyperplastic and/or adenomatous parathyroids; or total parathyroidectomy with healthy tissue reimplantation in the non-dominant forearm, in case of pathological involvement of all four parathyroids
MEN2A	Over 30 years	Single or multiglandular hyperplasia and/or adenoma	Specific resection on only the hyperplastic and/or adenomatous parathyroids
MEN4	Over 45 years	Single or multiglandular hyperplasia and/or adenoma	Specific resection on only the hyperplastic and/or adenomatous parathyroids
FHH	All ages	Multiglandular mildly hyperplastic parathyroids	Parathyroidectomy is not only unnecessary but also inappropriate, since it does not cure FHH-associated hypercalcemia
NSHPT	At birth or within the first six months of life	Multiglandular markedly hyperplastic parathyroids	Total parathyroidectomy
HPT-JT	Over 30 years	Single or multiglandular (usually two glands) cystic adenoma. Carcinomas in 10–15% of cases	Subtotal parathyroidectomy of adenomatous and/or carcinomatous parathyroids, or total parathyroidectomy, with healthy tissue reimplantation in the non-dominant forearm, in case of adenoma involvement of all four parathyroids
FIPH	N.R.	Single or multiglandular adenoma	Subtotal parathyroidectomy of adenomatous parathyroids, or total parathyroidectomy, with healthy tissue reimplantation in the non-dominant forearm, in case of adenoma involvement of all four parathyroids

N.R. = not reported. Footnotes: N.R. = not reported